flex_seed_scheme

5.0.0

Aug 24, 2026

The version requires Flutter 3.47.0 or higher. Offers support for SDK decoupled Material and Cupertino libraries.

BREAKING

• This version requires Flutter 3.47.0 or higher

• It also opts in on Dart 3.13.0 language features and lints.

• This release brings full support for the standalone material_ui and cupertino_ui packages.

• Per Flutter's official recommendation the package is released as a major breaking release, but contains no breaking APIs or any new APIs. Produced ColorScheme results are same as before too, with one intentional bug fix exception, see the surfaceTintTone fix below.

• FIX-BREAKING: The FlexTones.surfaceTintTone tone mapping is now actually applied to the produced ColorScheme.surfaceTint on the tones based generation path. It was always intended to be, but the produced scheme previously always assigned the produced primary color to ColorScheme.surfaceTint, silently ignoring the tone mapping. This bug fix changes produced ColorScheme.surfaceTint results for the built-in configurations FlexTones.ultraContrast, FlexTones.candyPop and FlexTones.chroma, whose custom surfaceTintTone (30 in light mode, 95 in dark mode) differs from their primary tone, as well as for custom FlexTones where surfaceTintTone differs from primaryTone. The built-ins vivid, vividSurfaces, vividBackground, highContrast and jolly define surfaceTintTone 30 in light mode where their primary tone is also 30, so their produced results do not change. The surfaceTint override parameter in SeedColorScheme.fromSeeds works as before. The MCU variant based path is unchanged and keeps surfaceTint equal to primary, matching Flutter's ColorScheme.fromSeed, which uses MaterialDynamicColors.primary and not MaterialDynamicColors.surfaceTint for the produced surfaceTint color. This is intentional Flutter parity: the two MCU colors differ when contrastLevel is not 0 and for the monochrome variant; a code comment now documents this so it is not mistaken for a bug. Usage of the surfaceTintTone feature is likely extremely rare, so consumer impact of its fix should be very low, and the new result is the originally intended one.

FIX

• FlexTones: the useCam16 property was missing from copyWith, operator ==, hashCode and debugFillProperties. Any copyWith call silently reset useCam16 to its default true, including the internal copyWith-based modifier expressiveOnContainer that SeedColorScheme.fromSeeds applies. This did not change any produced colors, since Cam16.fromInt and Hct.fromInt return the same hue and chroma for the same input color, which is also why the omission went unnoticed. Equality however wrongly reported two FlexTones configs differing only in useCam16 as equal. All four are fixed and debugFillProperties also gained the previously missing onErrorTone entry.

CHANGE DOCS

The changes below are only documentation and agent changes. No code behavior was changed.

• Reviewed and corrected the informational FlexSchemeVariant UI strings description and configDetails against the actual scheme generation code. As documented, these strings may change in any release and this is not a breaking change. No generated colors are affected.
  • expressive: config details tertiary palette uses Chroma 32 (not 24) and hue rotation range 15-120 degrees (not 20-120).
  • soft, vivid, highContrast and oneHue: config details neutral palette uses Chroma 6 (not 4). The value 4 was a leftover from before FSS 2.0.0, when the Material-3 default neutral chroma changed to 6.
  • fidelity and content: the descriptions were nearly identical, they now state their actual difference: tertiary palette is the seed color's complement (fidelity) versus an analogous hue (content).
  • vividBackground: description no longer refers to the deprecated background color swap, it now describes the actual difference to vividSurfaces (white surface in light mode, slightly darker surface in dark mode).
  • Aligned hue rotation phrasing: variants that also rotate a provided key color's hue (vibrant, expressive) now read "Hue from primary or key rotated x-y degrees", while variants that use a provided key hue as-is keep the "Hue primary rotated 60 degrees or key" form.
• Fixed stale doc comments that no longer matched the code:
  • FlexSchemeVariant.vividSurfaces: neutral chroma is 5 and neutralVariant 10, not 8 and 16.
  • FlexSchemeVariant.candyPop and FlexSchemeVariant.chroma: removed references to the removed background color and corrected surface tones (chroma uses light surface tone 99 and dark 4).
  • FlexTones.dark: default neutral chroma limits are 6 and 8, not 4 and 8.
  • FlexTones.candyPop: dark mode surface tone is 6, not 5.
  • FlexTones.chroma: light mode surface tone is 99 (not 98) and dark mode 4 (not 6).
• Codebase-wide documentation review, verified doc comment claims against the actual code and fixed stale information and typos. No code behavior was changed. Highlights:
  • FlexPaletteType.extended has 30 tones; docs variously claimed 24, 25, 26 and 27, and omitted the FSS extra tones 65, 75 and 84 from listings. Also corrected which extended tones are M3 spec additions versus FSS extras (2 and 97 are FSS extras).
  • Removed the stale FlexPaletteType narrative about the common type limiting chroma to max 40 for tones >= 90. That clamp was removed in FSS 2.0.0; the palette types now differ only in included tones.
  • FlexTones field docs: secondaryMinChroma and tertiaryMinChroma effective fallbacks are 0 (docs claimed 16 and 24); neutralChroma constructor default is 6 (doc claimed 4); onSecondaryFixedTone maps to onSecondaryFixed (doc said secondaryFixed); onSurfacesUseBW doc no longer claims it affects main on-colors.
  • Documented two known code quirks instead of changing behavior: FlexTones.copyWith does not include useCam16 (a copy always resets it to true) and produced ColorScheme.surfaceTint is always assigned primary, so FlexTones.surfaceTintTone is currently not applied. Both are candidates for actual code fixes in a future release.
  • FlexCorePalette docs: six palettes (not five), error palette defaults to hue 25 / chroma 84; code sample now uses value32bit instead of deprecated Color.value; "matching Flutter SDK" chroma claims qualified as pre Flutter 3.22 behavior.
  • MCU fork (comments only, all divergences from upstream text are listed in the mcu-fork-sync skill reference): corrected the stale useExpressiveOnContainerColors doc block (defaults to true since FSS 4.0.0 and only switches the light mode on-container tone, not the contrast curve), wrong color names on outline, onBackground and secondary docs, a duplicated Cam16 class doc, inverted L*/Y linearity claims, restored two "nonlinearity" comments corrupted by line reflow, added the missing Google license header to key_color.dart, removed a misleading "automatically generated" banner from the heavily customized scheme.dart, removed dead commented-out imports, and fixed assorted upstream typos.
  • Example app: updated stale UI text and comments that said expressive on-container colors are "not yet used by Flutter" (Flutter 3.44+ uses them, with no opt-out; FSS keeps the opt-out). Corrected "only depends on the SDK" claims to material_ui, wrong default value comments in custom_tones.dart, and assorted typos.
  • Repo docs and CI comments: dart format --fix no longer exists in Dart 3.13, commands updated in AGENTS.md and skills; CONTRIBUTING.md now says master branch; corrected stale workflow header comments (test.yml is the active CI, validate.yaml is disabled and used a removed flutter format command; web build no longer references a renderer flag).
• Reviewed the README against the code and updated stale information, typos and grammar. Screenshots are unchanged; they were made with earlier demo app versions but remain valid for documentation purposes. Highlights:
  • Corrected the predefined FlexTones configuration count to twelve (said eleven) and the pre-FSS 2.0.0 default value comments in the custom FlexTones code sample (primaryMinChroma, secondaryChroma and tertiaryChroma default to null, not 36/16/24).
  • Removed the stale description of the FlexPaletteType.common high-tone chroma clamp, deleted in FSS 2.0.0; the palette types now differ only in included tones.
  • Rewrote the resolved Flutter/MCU speculation in the expressive on-container section: Flutter stable 3.44 and later use MCU 0.13.0 with expressive on-containers as the only option, FSS keeps the opt-out. Also clarified that the FSS fork's flag only switches the light on-container tone 30/10, the contrast curve always follows the newer spec.
  • Fixed a broken code sample (Colors(0xFF555555) → Color(0xFF555555)), wrong sample comments (chroma variant labeled vibrant), and replaced a misleading example that chained onMainsUseBW().expressiveOnContainer(), where the second modifier was a no-op, with a working example plus a note about modifier order.
  • Fixed wrong symbol names (FlexTones.extended/FlexTones.common → FlexPaletteType.*), tonalSport → tonalSpot, FlexSeedSeed scheme → FlexSeedScheme, "FFS" → FSS, repeated "from a seeds", "none surface" → non-surface, and assorted grammar issues.
  • Added a "Version 5.0.0" note (Flutter 3.47/Dart 3.13 requirement, material_ui/cupertino_ui support, the surfaceTintTone fix), a headline bullet for respectMonochromeSeed, and a new "Color Channel Getters" section documenting the exported value32bit/alpha8bit/red8bit/green8bit/blue8bit extensions.
  • The Example Application section heading now links to the v5 demo.
• Agent/skills config: added a new release skill (pub.dev publish flow, GitHub release triggered web demo deploy, downstream coordination), added a "Verify claims against code" section with known stale-info traps and the FlexSchemeVariant string phrasing conventions to the code-documentation skill, and logged deliberate MCU comment divergences in the mcu-fork-sync skill reference. Also documented in the package-development skill that analysis_options.yaml is the versioned RydMike linter preferences file publicly shared as a gist, so rule changes to it or all_lint_rules.yaml get a CHANGELOG note and a reminder to update the gist.

TESTS

• Added full-scheme golden locks for FlexTones.candyPop and FlexTones.chroma, light and dark (FCS7.028, FCS7.029). Together with the existing ultraContrast goldens, all three tone mappings whose produced results changed with the surfaceTintTone fix are now locked against unintended changes.
• Added a test locking the legacy useExpressiveOnContainerColors: false on-container colors on the MCU variant path (FCS7.030). Coverage of those legacy branches was lost when other tests moved to the new expressive default.
• Added a no-op test for all six FlexTones modifiers called with a false flag (FTO1.15).
• Improved MCU fork test coverage and removed 14 coverage:ignore markers by adding tests for previously untested branches. These are extra coverage tests not done by MCU upstream. They will allow us to better verify our forked MCU version and detect changes made to MCU upstream in the future:
  • DynamicColor.getTone: background color landing in the awkward tone 50..60 zone, ToneDeltaPair with stayTogether in both light and dark mode, all dual background fallback branches, and the foregroundTone negligible-difference edge case.
  • TemperatureCache: analogous with more divisions than hue steps and with count larger than divisions, plus cached complement and inputRelativeTemperature calls.
  • Score.score fallback color when all input colors are filtered out.
  • QuantizerWsmeans empty cluster reset when a starting cluster captures no points.
  • Covered the last IDE-reported coverage misses: the identical equality short circuits in CorePalette and CorePalettes (self comparison tests) and the awkward-zone adjustment to tone 60 in DynamicColor.getTone, used when tone 49 cannot reach the required contrast against a dark background.
  • The package now has 100% line coverage with only 8 remaining ignore markers, all on verified dead code: compile-time disabled debug logging in QuantizerWsmeans, negative modulo guards in MathUtils that Dart's % operator can never produce, index guards in TemperatureCache.analogous that its callers can never trigger, and one unreachable defensive padding line.
• Added regression tests for the FlexTones useCam16 fix: equality of configs differing only in useCam16 (FTO1.02c) and copyWith/modifier preservation of useCam16 (FTO1.09d).
• Updated the FlexTones toString golden for the added onErrorTone and useCam16 diagnostics properties.
• Corrected the expected configurations in FTO1.017/FTO1.018: they omitted useCam16: false for FlexTones.material, which the previous incomplete equality operator could not detect.
• Update tests to no longer use useExpressiveOnContainerColors: false for all MCU DynamicSchemeVariants. This is no longer needed as the default is now true in Flutter stable 3.44.0 and later. The option to not use expressive on container colors is still available and can be used by setting useExpressiveOnContainerColors to false when calling SeedColorScheme.fromSeeds. However, Flutter's ColorScheme.fromSeed does not use expressive on container colors anymore, nor does it offer it as an option. With FlexSeedScheme it is still available and can be used as before. The SeedColorScheme.fromSeeds parameter useExpressiveOnContainerColors already defaulted to true instead of false in FSS version 4.0.0, and started using it as default before Flutter switched to it. You can still use the legacy option if you need it.

CHORE

• Bump all dependencies.
• Publishing: resolved both dart pub publish --dry-run warnings and reduced the published package archive from 13 MB to about 0.5 MB.
  • Untracked the git-ignored, Flutter tool generated example platform files (generated_plugin_registrant.*, generated_plugins.cmake and GeneratedPluginRegistrant.swift for Windows, Linux and macOS). They are regenerated by flutter pub get and builds, and current Flutter project templates git-ignore them. They are no longer part of the published package either.
  • Added a root .pubignore. It restates the publishing-relevant .gitignore rules (a .pubignore replaces the .gitignore in the same directory for publishing decisions) and additionally excludes internal repository content from the published archive: AGENTS.md, docs/, scripts/, and the README image folder doc_assets/. The README references its images via absolute GitHub URLs, so pub.dev does not need them in the archive. Excluding docs/ also resolves the pub layout warning about a plural top-level docs directory. The example/screenshots/ folder is intentionally still published: its files are declared in the pubspec screenshots: section and the pub.dev server rejects the upload if they are missing from the archive, a check the local dry run does not perform.
• CI: bumped codecov/codecov-action from the end-of-life v3 to v5 in all three workflows and renamed its file: input to files: per the v4+ API. The -dev.1 release will serve as a live test of the deploy workflow.
• Verified included MCU fork to be at parity with MCU 0.13.1. It was stated to be at 0.13.0 parity before this release. Flutter 3.47 just started using MCU 0.13.0. A check revealed that MCU 0.13.1 is a small internal change, that we also already had in FSS version 4.0.0, it was added before it was published in MCU.
  • The new Cam16 hue helper was already in FSS version 4.0.0; MCU 0.13.1 published that commit.
  • This release is only a doc update about Scheme migration URL + declare fork at 0.13.1 (Flutter 3.47 still on 0.13.0).
  • No user-facing ColorScheme / HCT change.
• Example app's macOS and iOS builds migrated from CocoaPods to Swift Package Manager.
• Code style: Changed from RydMike lints 2.6.0 to RydMike lints 3.0.0. Big code diffs and changes in the code style.
• Updated to opt in on using min Dart 3.13.0 SDK.
  • Old code base was compile time incompatible with Dart 3.13.0, fixed the issues that don't compile with Dart 3.13.0. The issue was this breaking change in Dart 3.13:
    • Restriction on final and var in normal function parameters: With primary constructors, using final or var on formal parameters in normal functions becomes a compile-time error.
    • They are reserved exclusively for declaring parameters in primary constructors. Note that the lints avoid_final_parameters and var_with_no_type_annotation only work with a language version of Dart 3.12 or lower.
    • To enforce immutable parameters as a style choice in Dart 3.13 and later, use the parameter_assignments linter rule, which this repo already always enforced. See https://dart.dev/language/primary-constructors
• Fixed all new lints that came with Dart 3.13.
• Example app: Fixed Flutter SDK deprecation of axisAlignment in ListTileReveal and SwitchListTileReveal widgets.
• Example app: Temporary use of MaterialUiCompatibilityBridge.
  • Used as temporary fix for MaterialUi compatibility for packages that still use Material from SDK, pre Flutter 3.47.0. It is in the example app used for the not yet updated FlexColorPicker that the example app uses.
  • The color picker will be updated next and then this temporary fix will be removed and a 5.0.1 release will be published. It is a bit of a chicken and egg situation. The color picker also uses this package, and we need to publish a version of this package first, then update the picker and then update this package again so its example app can use the new version of the picker and remove the MaterialUiCompatibilityBridge.

Aug 24, 2026

The version requires Flutter 3.47.0 or higher. Offers support for SDK decoupled Material and Cupertino libraries.

BREAKING

• This version requires Flutter 3.47.0 or higher

• It also opts in on Dart 3.13.0 language features and lints.

• This release brings full support for the standalone material_ui and cupertino_ui packages.

• Per Flutter's official recommendation the package is released as a major breaking release, but contains no breaking APIs or any new APIs. Produced ColorScheme results are same as before too, with one intentional bug fix exception, see the surfaceTintTone fix below.

• FIX-BREAKING: The FlexTones.surfaceTintTone tone mapping is now actually applied to the produced ColorScheme.surfaceTint on the tones based generation path. It was always intended to be, but the produced scheme previously always assigned the produced primary color to ColorScheme.surfaceTint, silently ignoring the tone mapping. This bug fix changes produced ColorScheme.surfaceTint results for the built-in configurations FlexTones.ultraContrast, FlexTones.candyPop and FlexTones.chroma, whose custom surfaceTintTone (30 in light mode, 95 in dark mode) differs from their primary tone, as well as for custom FlexTones where surfaceTintTone differs from primaryTone. The built-ins vivid, vividSurfaces, vividBackground, highContrast and jolly define surfaceTintTone 30 in light mode where their primary tone is also 30, so their produced results do not change. The surfaceTint override parameter in SeedColorScheme.fromSeeds works as before. The MCU variant based path is unchanged and keeps surfaceTint equal to primary, matching Flutter's ColorScheme.fromSeed, which uses MaterialDynamicColors.primary and not MaterialDynamicColors.surfaceTint for the produced surfaceTint color. This is intentional Flutter parity: the two MCU colors differ when contrastLevel is not 0 and for the monochrome variant; a code comment now documents this so it is not mistaken for a bug. Usage of the surfaceTintTone feature is likely extremely rare, so consumer impact of its fix should be very low, and the new result is the originally intended one.

FIX

• FlexTones: the useCam16 property was missing from copyWith, operator ==, hashCode and debugFillProperties. Any copyWith call silently reset useCam16 to its default true, including the internal copyWith-based modifier expressiveOnContainer that SeedColorScheme.fromSeeds applies. This did not change any produced colors, since Cam16.fromInt and Hct.fromInt return the same hue and chroma for the same input color, which is also why the omission went unnoticed. Equality however wrongly reported two FlexTones configs differing only in useCam16 as equal. All four are fixed and debugFillProperties also gained the previously missing onErrorTone entry.

CHANGE DOCS

The changes below are only documentation and agent changes. No code behavior was changed.

• Reviewed and corrected the informational FlexSchemeVariant UI strings description and configDetails against the actual scheme generation code. As documented, these strings may change in any release and this is not a breaking change. No generated colors are affected.
  • expressive: config details tertiary palette uses Chroma 32 (not 24) and hue rotation range 15-120 degrees (not 20-120).
  • soft, vivid, highContrast and oneHue: config details neutral palette uses Chroma 6 (not 4). The value 4 was a leftover from before FSS 2.0.0, when the Material-3 default neutral chroma changed to 6.
  • fidelity and content: the descriptions were nearly identical, they now state their actual difference: tertiary palette is the seed color's complement (fidelity) versus an analogous hue (content).
  • vividBackground: description no longer refers to the deprecated background color swap, it now describes the actual difference to vividSurfaces (white surface in light mode, slightly darker surface in dark mode).
  • Aligned hue rotation phrasing: variants that also rotate a provided key color's hue (vibrant, expressive) now read "Hue from primary or key rotated x-y degrees", while variants that use a provided key hue as-is keep the "Hue primary rotated 60 degrees or key" form.
• Fixed stale doc comments that no longer matched the code:
  • FlexSchemeVariant.vividSurfaces: neutral chroma is 5 and neutralVariant 10, not 8 and 16.
  • FlexSchemeVariant.candyPop and FlexSchemeVariant.chroma: removed references to the removed background color and corrected surface tones (chroma uses light surface tone 99 and dark 4).
  • FlexTones.dark: default neutral chroma limits are 6 and 8, not 4 and 8.
  • FlexTones.candyPop: dark mode surface tone is 6, not 5.
  • FlexTones.chroma: light mode surface tone is 99 (not 98) and dark mode 4 (not 6).
• Codebase-wide documentation review, verified doc comment claims against the actual code and fixed stale information and typos. No code behavior was changed. Highlights:
  • FlexPaletteType.extended has 30 tones; docs variously claimed 24, 25, 26 and 27, and omitted the FSS extra tones 65, 75 and 84 from listings. Also corrected which extended tones are M3 spec additions versus FSS extras (2 and 97 are FSS extras).
  • Removed the stale FlexPaletteType narrative about the common type limiting chroma to max 40 for tones >= 90. That clamp was removed in FSS 2.0.0; the palette types now differ only in included tones.
  • FlexTones field docs: secondaryMinChroma and tertiaryMinChroma effective fallbacks are 0 (docs claimed 16 and 24); neutralChroma constructor default is 6 (doc claimed 4); onSecondaryFixedTone maps to onSecondaryFixed (doc said secondaryFixed); onSurfacesUseBW doc no longer claims it affects main on-colors.
  • Documented two known code quirks instead of changing behavior: FlexTones.copyWith does not include useCam16 (a copy always resets it to true) and produced ColorScheme.surfaceTint is always assigned primary, so FlexTones.surfaceTintTone is currently not applied. Both are candidates for actual code fixes in a future release.
  • FlexCorePalette docs: six palettes (not five), error palette defaults to hue 25 / chroma 84; code sample now uses value32bit instead of deprecated Color.value; "matching Flutter SDK" chroma claims qualified as pre Flutter 3.22 behavior.
  • MCU fork (comments only, all divergences from upstream text are listed in the mcu-fork-sync skill reference): corrected the stale useExpressiveOnContainerColors doc block (defaults to true since FSS 4.0.0 and only switches the light mode on-container tone, not the contrast curve), wrong color names on outline, onBackground and secondary docs, a duplicated Cam16 class doc, inverted L*/Y linearity claims, restored two "nonlinearity" comments corrupted by line reflow, added the missing Google license header to key_color.dart, removed a misleading "automatically generated" banner from the heavily customized scheme.dart, removed dead commented-out imports, and fixed assorted upstream typos.
  • Example app: updated stale UI text and comments that said expressive on-container colors are "not yet used by Flutter" (Flutter 3.44+ uses them, with no opt-out; FSS keeps the opt-out). Corrected "only depends on the SDK" claims to material_ui, wrong default value comments in custom_tones.dart, and assorted typos.
  • Repo docs and CI comments: dart format --fix no longer exists in Dart 3.13, commands updated in AGENTS.md and skills; CONTRIBUTING.md now says master branch; corrected stale workflow header comments (test.yml is the active CI, validate.yaml is disabled and used a removed flutter format command; web build no longer references a renderer flag).
• Reviewed the README against the code and updated stale information, typos and grammar. Screenshots are unchanged; they were made with earlier demo app versions but remain valid for documentation purposes. Highlights:
  • Corrected the predefined FlexTones configuration count to twelve (said eleven) and the pre-FSS 2.0.0 default value comments in the custom FlexTones code sample (primaryMinChroma, secondaryChroma and tertiaryChroma default to null, not 36/16/24).
  • Removed the stale description of the FlexPaletteType.common high-tone chroma clamp, deleted in FSS 2.0.0; the palette types now differ only in included tones.
  • Rewrote the resolved Flutter/MCU speculation in the expressive on-container section: Flutter stable 3.44 and later use MCU 0.13.0 with expressive on-containers as the only option, FSS keeps the opt-out. Also clarified that the FSS fork's flag only switches the light on-container tone 30/10, the contrast curve always follows the newer spec.
  • Fixed a broken code sample (Colors(0xFF555555) → Color(0xFF555555)), wrong sample comments (chroma variant labeled vibrant), and replaced a misleading example that chained onMainsUseBW().expressiveOnContainer(), where the second modifier was a no-op, with a working example plus a note about modifier order.
  • Fixed wrong symbol names (FlexTones.extended/FlexTones.common → FlexPaletteType.*), tonalSport → tonalSpot, FlexSeedSeed scheme → FlexSeedScheme, "FFS" → FSS, repeated "from a seeds", "none surface" → non-surface, and assorted grammar issues.
  • Added a "Version 5.0.0" note (Flutter 3.47/Dart 3.13 requirement, material_ui/cupertino_ui support, the surfaceTintTone fix), a headline bullet for respectMonochromeSeed, and a new "Color Channel Getters" section documenting the exported value32bit/alpha8bit/red8bit/green8bit/blue8bit extensions.
  • The Example Application section heading now links to the v5 demo.
• Agent/skills config: added a new release skill (pub.dev publish flow, GitHub release triggered web demo deploy, downstream coordination), added a "Verify claims against code" section with known stale-info traps and the FlexSchemeVariant string phrasing conventions to the code-documentation skill, and logged deliberate MCU comment divergences in the mcu-fork-sync skill reference. Also documented in the package-development skill that analysis_options.yaml is the versioned RydMike linter preferences file publicly shared as a gist, so rule changes to it or all_lint_rules.yaml get a CHANGELOG note and a reminder to update the gist.

TESTS

• Added full-scheme golden locks for FlexTones.candyPop and FlexTones.chroma, light and dark (FCS7.028, FCS7.029). Together with the existing ultraContrast goldens, all three tone mappings whose produced results changed with the surfaceTintTone fix are now locked against unintended changes.
• Added a test locking the legacy useExpressiveOnContainerColors: false on-container colors on the MCU variant path (FCS7.030). Coverage of those legacy branches was lost when other tests moved to the new expressive default.
• Added a no-op test for all six FlexTones modifiers called with a false flag (FTO1.15).
• Improved MCU fork test coverage and removed 14 coverage:ignore markers by adding tests for previously untested branches. These are extra coverage tests not done by MCU upstream. They will allow us to better verify our forked MCU version and detect changes made to MCU upstream in the future:
  • DynamicColor.getTone: background color landing in the awkward tone 50..60 zone, ToneDeltaPair with stayTogether in both light and dark mode, all dual background fallback branches, and the foregroundTone negligible-difference edge case.
  • TemperatureCache: analogous with more divisions than hue steps and with count larger than divisions, plus cached complement and inputRelativeTemperature calls.
  • Score.score fallback color when all input colors are filtered out.
  • QuantizerWsmeans empty cluster reset when a starting cluster captures no points.
  • Covered the last IDE-reported coverage misses: the identical equality short circuits in CorePalette and CorePalettes (self comparison tests) and the awkward-zone adjustment to tone 60 in DynamicColor.getTone, used when tone 49 cannot reach the required contrast against a dark background.
  • The package now has 100% line coverage with only 8 remaining ignore markers, all on verified dead code: compile-time disabled debug logging in QuantizerWsmeans, negative modulo guards in MathUtils that Dart's % operator can never produce, index guards in TemperatureCache.analogous that its callers can never trigger, and one unreachable defensive padding line.
• Added regression tests for the FlexTones useCam16 fix: equality of configs differing only in useCam16 (FTO1.02c) and copyWith/modifier preservation of useCam16 (FTO1.09d).
• Updated the FlexTones toString golden for the added onErrorTone and useCam16 diagnostics properties.
• Corrected the expected configurations in FTO1.017/FTO1.018: they omitted useCam16: false for FlexTones.material, which the previous incomplete equality operator could not detect.
• Update tests to no longer use useExpressiveOnContainerColors: false for all MCU DynamicSchemeVariants. This is no longer needed as the default is now true in Flutter stable 3.44.0 and later. The option to not use expressive on container colors is still available and can be used by setting useExpressiveOnContainerColors to false when calling SeedColorScheme.fromSeeds. However, Flutter's ColorScheme.fromSeed does not use expressive on container colors anymore, nor does it offer it as an option. With FlexSeedScheme it is still available and can be used as before. The SeedColorScheme.fromSeeds parameter useExpressiveOnContainerColors already defaulted to true instead of false in FSS version 4.0.0, and started using it as default before Flutter switched to it. You can still use the legacy option if you need it.

CHORE

• Bump all dependencies.
• Publishing: resolved both dart pub publish --dry-run warnings and reduced the published package archive from 13 MB to about 0.5 MB.
  • Untracked the git-ignored, Flutter tool generated example platform files (generated_plugin_registrant.*, generated_plugins.cmake and GeneratedPluginRegistrant.swift for Windows, Linux and macOS). They are regenerated by flutter pub get and builds, and current Flutter project templates git-ignore them. They are no longer part of the published package either.
  • Added a root .pubignore. It restates the publishing-relevant .gitignore rules (a .pubignore replaces the .gitignore in the same directory for publishing decisions) and additionally excludes internal repository content from the published archive: AGENTS.md, docs/, scripts/, and the README image folder doc_assets/. The README references its images via absolute GitHub URLs, so pub.dev does not need them in the archive. Excluding docs/ also resolves the pub layout warning about a plural top-level docs directory. The example/screenshots/ folder is intentionally still published: its files are declared in the pubspec screenshots: section and the pub.dev server rejects the upload if they are missing from the archive, a check the local dry run does not perform.
• CI: bumped codecov/codecov-action from the end-of-life v3 to v5 in all three workflows and renamed its file: input to files: per the v4+ API. The -dev.1 release will serve as a live test of the deploy workflow.
• Verified included MCU fork to be at parity with MCU 0.13.1. It was stated to be at 0.13.0 parity before this release. Flutter 3.47 just started using MCU 0.13.0. A check revealed that MCU 0.13.1 is a small internal change, that we also already had in FSS version 4.0.0, it was added before it was published in MCU.
  • The new Cam16 hue helper was already in FSS version 4.0.0; MCU 0.13.1 published that commit.
  • This release is only a doc update about Scheme migration URL + declare fork at 0.13.1 (Flutter 3.47 still on 0.13.0).
  • No user-facing ColorScheme / HCT change.
• Example app's macOS and iOS builds migrated from CocoaPods to Swift Package Manager.
• Code style: Changed from RydMike lints 2.6.0 to RydMike lints 3.0.0. Big code diffs and changes in the code style.
• Updated to opt in on using min Dart 3.13.0 SDK.
  • Old code base was compile time incompatible with Dart 3.13.0, fixed the issues that don't compile with Dart 3.13.0. The issue was this breaking change in Dart 3.13:
    • Restriction on final and var in normal function parameters: With primary constructors, using final or var on formal parameters in normal functions becomes a compile-time error.
    • They are reserved exclusively for declaring parameters in primary constructors. Note that the lints avoid_final_parameters and var_with_no_type_annotation only work with a language version of Dart 3.12 or lower.
    • To enforce immutable parameters as a style choice in Dart 3.13 and later, use the parameter_assignments linter rule, which this repo already always enforced. See https://dart.dev/language/primary-constructors
• Fixed all new lints that came with Dart 3.13.
• Example app: Fixed Flutter SDK deprecation of axisAlignment in ListTileReveal and SwitchListTileReveal widgets.
• Example app: Temporary use of MaterialUiCompatibilityBridge.
  • Used as temporary fix for MaterialUi compatibility for packages that still use Material from SDK, pre Flutter 3.47.0. It is in the example app used for the not yet updated FlexColorPicker that the example app uses.
  • The color picker will be updated next and then this temporary fix will be removed and a 5.0.1 release will be published. It is a bit of a chicken and egg situation. The color picker also uses this package, and we need to publish a version of this package first, then update the picker and then update this package again so its example app can use the new version of the picker and remove the MaterialUiCompatibilityBridge.

5.0.0-dev.1

Aug 24, 2026

The version requires Flutter 3.47.0 or higher. Offers support for SDK decoupled Material and Cupertino libraries.

BREAKING

• This version requires Flutter 3.47.0 or higher

• It also opts in on Dart 3.13.0 language features and lints.

• This release brings full support for the standalone material_ui and cupertino_ui packages.

• Per Flutter's official recommendation the package is released as a major breaking release, but contains no breaking APIs or any new APIs. Produced ColorScheme results are same as before too, with one intentional bug fix exception, see the surfaceTintTone fix below.

• FIX-BREAKING: The FlexTones.surfaceTintTone tone mapping is now actually applied to the produced ColorScheme.surfaceTint on the tones based generation path. It was always intended to be, but the produced scheme previously always assigned the produced primary color to ColorScheme.surfaceTint, silently ignoring the tone mapping. This bug fix changes produced ColorScheme.surfaceTint results for the built-in configurations FlexTones.ultraContrast, FlexTones.candyPop and FlexTones.chroma, whose custom surfaceTintTone (30 in light mode, 95 in dark mode) differs from their primary tone, as well as for custom FlexTones where surfaceTintTone differs from primaryTone. The built-ins vivid, vividSurfaces, vividBackground, highContrast and jolly define surfaceTintTone 30 in light mode where their primary tone is also 30, so their produced results do not change. The surfaceTint override parameter in SeedColorScheme.fromSeeds works as before. The MCU variant based path is unchanged and keeps surfaceTint equal to primary, matching Flutter's ColorScheme.fromSeed, which uses MaterialDynamicColors.primary and not MaterialDynamicColors.surfaceTint for the produced surfaceTint color. This is intentional Flutter parity: the two MCU colors differ when contrastLevel is not 0 and for the monochrome variant; a code comment now documents this so it is not mistaken for a bug. Usage of the surfaceTintTone feature is likely extremely rare, so consumer impact of its fix should be very low, and the new result is the originally intended one.

FIX

• FlexTones: the useCam16 property was missing from copyWith, operator ==, hashCode and debugFillProperties. Any copyWith call silently reset useCam16 to its default true, including the internal copyWith-based modifier expressiveOnContainer that SeedColorScheme.fromSeeds applies. This did not change any produced colors, since Cam16.fromInt and Hct.fromInt return the same hue and chroma for the same input color, which is also why the omission went unnoticed. Equality however wrongly reported two FlexTones configs differing only in useCam16 as equal. All four are fixed and debugFillProperties also gained the previously missing onErrorTone entry.

CHANGE DOCS

The changes below are only documentation and agent changes. No code behavior was changed.

• Reviewed and corrected the informational FlexSchemeVariant UI strings description and configDetails against the actual scheme generation code. As documented, these strings may change in any release and this is not a breaking change. No generated colors are affected.
  • expressive: config details tertiary palette uses Chroma 32 (not 24) and hue rotation range 15-120 degrees (not 20-120).
  • soft, vivid, highContrast and oneHue: config details neutral palette uses Chroma 6 (not 4). The value 4 was a leftover from before FSS 2.0.0, when the Material-3 default neutral chroma changed to 6.
  • fidelity and content: the descriptions were nearly identical, they now state their actual difference: tertiary palette is the seed color's complement (fidelity) versus an analogous hue (content).
  • vividBackground: description no longer refers to the deprecated background color swap, it now describes the actual difference to vividSurfaces (white surface in light mode, slightly darker surface in dark mode).
  • Aligned hue rotation phrasing: variants that also rotate a provided key color's hue (vibrant, expressive) now read "Hue from primary or key rotated x-y degrees", while variants that use a provided key hue as-is keep the "Hue primary rotated 60 degrees or key" form.
• Fixed stale doc comments that no longer matched the code:
  • FlexSchemeVariant.vividSurfaces: neutral chroma is 5 and neutralVariant 10, not 8 and 16.
  • FlexSchemeVariant.candyPop and FlexSchemeVariant.chroma: removed references to the removed background color and corrected surface tones (chroma uses light surface tone 99 and dark 4).
  • FlexTones.dark: default neutral chroma limits are 6 and 8, not 4 and 8.
  • FlexTones.candyPop: dark mode surface tone is 6, not 5.
  • FlexTones.chroma: light mode surface tone is 99 (not 98) and dark mode 4 (not 6).
• Codebase-wide documentation review, verified doc comment claims against the actual code and fixed stale information and typos. No code behavior was changed. Highlights:
  • FlexPaletteType.extended has 30 tones; docs variously claimed 24, 25, 26 and 27, and omitted the FSS extra tones 65, 75 and 84 from listings. Also corrected which extended tones are M3 spec additions versus FSS extras (2 and 97 are FSS extras).
  • Removed the stale FlexPaletteType narrative about the common type limiting chroma to max 40 for tones >= 90. That clamp was removed in FSS 2.0.0; the palette types now differ only in included tones.
  • FlexTones field docs: secondaryMinChroma and tertiaryMinChroma effective fallbacks are 0 (docs claimed 16 and 24); neutralChroma constructor default is 6 (doc claimed 4); onSecondaryFixedTone maps to onSecondaryFixed (doc said secondaryFixed); onSurfacesUseBW doc no longer claims it affects main on-colors.
  • Documented two known code quirks instead of changing behavior: FlexTones.copyWith does not include useCam16 (a copy always resets it to true) and produced ColorScheme.surfaceTint is always assigned primary, so FlexTones.surfaceTintTone is currently not applied. Both are candidates for actual code fixes in a future release.
  • FlexCorePalette docs: six palettes (not five), error palette defaults to hue 25 / chroma 84; code sample now uses value32bit instead of deprecated Color.value; "matching Flutter SDK" chroma claims qualified as pre Flutter 3.22 behavior.
  • MCU fork (comments only, all divergences from upstream text are listed in the mcu-fork-sync skill reference): corrected the stale useExpressiveOnContainerColors doc block (defaults to true since FSS 4.0.0 and only switches the light mode on-container tone, not the contrast curve), wrong color names on outline, onBackground and secondary docs, a duplicated Cam16 class doc, inverted L*/Y linearity claims, restored two "nonlinearity" comments corrupted by line reflow, added the missing Google license header to key_color.dart, removed a misleading "automatically generated" banner from the heavily customized scheme.dart, removed dead commented-out imports, and fixed assorted upstream typos.
  • Example app: updated stale UI text and comments that said expressive on-container colors are "not yet used by Flutter" (Flutter 3.44+ uses them, with no opt-out; FSS keeps the opt-out). Corrected "only depends on the SDK" claims to material_ui, wrong default value comments in custom_tones.dart, and assorted typos.
  • Repo docs and CI comments: dart format --fix no longer exists in Dart 3.13, commands updated in AGENTS.md and skills; CONTRIBUTING.md now says master branch; corrected stale workflow header comments (test.yml is the active CI, validate.yaml is disabled and used a removed flutter format command; web build no longer references a renderer flag).
• Reviewed the README against the code and updated stale information, typos and grammar. Screenshots are unchanged; they were made with earlier demo app versions but remain valid for documentation purposes. Highlights:
  • Corrected the predefined FlexTones configuration count to twelve (said eleven) and the pre-FSS 2.0.0 default value comments in the custom FlexTones code sample (primaryMinChroma, secondaryChroma and tertiaryChroma default to null, not 36/16/24).
  • Removed the stale description of the FlexPaletteType.common high-tone chroma clamp, deleted in FSS 2.0.0; the palette types now differ only in included tones.
  • Rewrote the resolved Flutter/MCU speculation in the expressive on-container section: Flutter stable 3.44 and later use MCU 0.13.0 with expressive on-containers as the only option, FSS keeps the opt-out. Also clarified that the FSS fork's flag only switches the light on-container tone 30/10, the contrast curve always follows the newer spec.
  • Fixed a broken code sample (Colors(0xFF555555) → Color(0xFF555555)), wrong sample comments (chroma variant labeled vibrant), and replaced a misleading example that chained onMainsUseBW().expressiveOnContainer(), where the second modifier was a no-op, with a working example plus a note about modifier order.
  • Fixed wrong symbol names (FlexTones.extended/FlexTones.common → FlexPaletteType.*), tonalSport → tonalSpot, FlexSeedSeed scheme → FlexSeedScheme, "FFS" → FSS, repeated "from a seeds", "none surface" → non-surface, and assorted grammar issues.
  • Added a "Version 5.0.0" note (Flutter 3.47/Dart 3.13 requirement, material_ui/cupertino_ui support, the surfaceTintTone fix), a headline bullet for respectMonochromeSeed, and a new "Color Channel Getters" section documenting the exported value32bit/alpha8bit/red8bit/green8bit/blue8bit extensions.
  • The Example Application section heading now links to the v5 demo.
• Agent/skills config: added a new release skill (pub.dev publish flow, GitHub release triggered web demo deploy, downstream coordination), added a "Verify claims against code" section with known stale-info traps and the FlexSchemeVariant string phrasing conventions to the code-documentation skill, and logged deliberate MCU comment divergences in the mcu-fork-sync skill reference. Also documented in the package-development skill that analysis_options.yaml is the versioned RydMike linter preferences file publicly shared as a gist, so rule changes to it or all_lint_rules.yaml get a CHANGELOG note and a reminder to update the gist.

TESTS

• Added full-scheme golden locks for FlexTones.candyPop and FlexTones.chroma, light and dark (FCS7.028, FCS7.029). Together with the existing ultraContrast goldens, all three tone mappings whose produced results changed with the surfaceTintTone fix are now locked against unintended changes.
• Added a test locking the legacy useExpressiveOnContainerColors: false on-container colors on the MCU variant path (FCS7.030). Coverage of those legacy branches was lost when other tests moved to the new expressive default.
• Added a no-op test for all six FlexTones modifiers called with a false flag (FTO1.15).
• Improved MCU fork test coverage and removed 14 coverage:ignore markers by adding tests for previously untested branches. These are extra coverage tests not done by MCU upstream. They will allow us to better verify our forked MCU version and detect changes made to MCU upstream in the future:
  • DynamicColor.getTone: background color landing in the awkward tone 50..60 zone, ToneDeltaPair with stayTogether in both light and dark mode, all dual background fallback branches, and the foregroundTone negligible-difference edge case.
  • TemperatureCache: analogous with more divisions than hue steps and with count larger than divisions, plus cached complement and inputRelativeTemperature calls.
  • Score.score fallback color when all input colors are filtered out.
  • QuantizerWsmeans empty cluster reset when a starting cluster captures no points.
  • Covered the last IDE-reported coverage misses: the identical equality short circuits in CorePalette and CorePalettes (self comparison tests) and the awkward-zone adjustment to tone 60 in DynamicColor.getTone, used when tone 49 cannot reach the required contrast against a dark background.
  • The package now has 100% line coverage with only 8 remaining ignore markers, all on verified dead code: compile-time disabled debug logging in QuantizerWsmeans, negative modulo guards in MathUtils that Dart's % operator can never produce, index guards in TemperatureCache.analogous that its callers can never trigger, and one unreachable defensive padding line.
• Added regression tests for the FlexTones useCam16 fix: equality of configs differing only in useCam16 (FTO1.02c) and copyWith/modifier preservation of useCam16 (FTO1.09d).
• Updated the FlexTones toString golden for the added onErrorTone and useCam16 diagnostics properties.
• Corrected the expected configurations in FTO1.017/FTO1.018: they omitted useCam16: false for FlexTones.material, which the previous incomplete equality operator could not detect.
• Update tests to no longer use useExpressiveOnContainerColors: false for all MCU DynamicSchemeVariants. This is no longer needed as the default is now true in Flutter stable 3.44.0 and later. The option to not use expressive on container colors is still available and can be used by setting useExpressiveOnContainerColors to false when calling SeedColorScheme.fromSeeds. However, Flutter's ColorScheme.fromSeed does not use expressive on container colors anymore, nor does it offer it as an option. With FlexSeedScheme it is still available and can be used as before. The SeedColorScheme.fromSeeds parameter useExpressiveOnContainerColors already defaulted to true instead of false in FSS version 4.0.0, and started using it as default before Flutter switched to it. You can still use the legacy option if you need it.

CHORE

• Bump all dependencies.
• Publishing: resolved both dart pub publish --dry-run warnings and reduced the published package archive from 13 MB to about 0.5 MB.
  • Untracked the git-ignored, Flutter tool generated example platform files (generated_plugin_registrant.*, generated_plugins.cmake and GeneratedPluginRegistrant.swift for Windows, Linux and macOS). They are regenerated by flutter pub get and builds, and current Flutter project templates git-ignore them. They are no longer part of the published package either.
  • Added a root .pubignore. It restates the publishing-relevant .gitignore rules (a .pubignore replaces the .gitignore in the same directory for publishing decisions) and additionally excludes internal repository content from the published archive: AGENTS.md, docs/, scripts/, and the README image folder doc_assets/. The README references its images via absolute GitHub URLs, so pub.dev does not need them in the archive. Excluding docs/ also resolves the pub layout warning about a plural top-level docs directory. The example/screenshots/ folder is intentionally still published: its files are declared in the pubspec screenshots: section and the pub.dev server rejects the upload if they are missing from the archive, a check the local dry run does not perform.
• CI: bumped codecov/codecov-action from the end-of-life v3 to v5 in all three workflows and renamed its file: input to files: per the v4+ API. The -dev.1 release will serve as a live test of the deploy workflow.
• Verified included MCU fork to be at parity with MCU 0.13.1. It was stated to be at 0.13.0 parity before this release. Flutter 3.47 just started using MCU 0.13.0. A check revealed that MCU 0.13.1 is a small internal change, that we also already had in FSS version 4.0.0, it was added before it was published in MCU.
  • The new Cam16 hue helper was already in FSS version 4.0.0; MCU 0.13.1 published that commit.
  • This release is only a doc update about Scheme migration URL + declare fork at 0.13.1 (Flutter 3.47 still on 0.13.0).
  • No user-facing ColorScheme / HCT change.
• Example app's macOS and iOS builds migrated from CocoaPods to Swift Package Manager.
• Code style: Changed from RydMike lints 2.6.0 to RydMike lints 3.0.0. Big code diffs and changes in the code style.
• Updated to opt in on using min Dart 3.13.0 SDK.
  • Old code base was compile time incompatible with Dart 3.13.0, fixed the issues that don't compile with Dart 3.13.0. The issue was this breaking change in Dart 3.13:
    • Restriction on final and var in normal function parameters: With primary constructors, using final or var on formal parameters in normal functions becomes a compile-time error.
    • They are reserved exclusively for declaring parameters in primary constructors. Note that the lints avoid_final_parameters and var_with_no_type_annotation only work with a language version of Dart 3.12 or lower.
    • To enforce immutable parameters as a style choice in Dart 3.13 and later, use the parameter_assignments linter rule, which this repo already always enforced. See https://dart.dev/language/primary-constructors
• Fixed all new lints that came with Dart 3.13.
• Example app: Fixed Flutter SDK deprecation of axisAlignment in ListTileReveal and SwitchListTileReveal widgets.
• Example app: Temporary use of MaterialUiCompatibilityBridge.
  • Used as temporary fix for MaterialUi compatibility for packages that still use Material from SDK, pre Flutter 3.47.0. It is in the example app used for the not yet updated FlexColorPicker that the example app uses.
  • The color picker will be updated next and then this temporary fix will be removed and a 5.0.1 release will be published. It is a bit of a chicken and egg situation. The color picker also uses this package, and we need to publish a version of this package first, then update the picker and then update this package again so its example app can use the new version of the picker and remove the MaterialUiCompatibilityBridge.

Version 4.0.1

Nov 23, 2025

The version requires Flutter 3.38.0 or higher.

FIX

• Fix mistakes in README.md section about useExpressiveOnContainerColors.

Nov 23, 2025

The version requires Flutter 3.38.0 or higher.

FIX

• Fix mistakes in README.md section about useExpressiveOnContainerColors.

Version 4.0.0

Nov 22, 2025

The version requires Flutter 3.38.0 or higher.

This release really brings the bundled forked version of the package Material Color Utilities (MCU) to parity with version 0.13.0. Flutter stable 3.38.x still uses MCU 0.11.1. Next version of Flutter, after stable 0.38, will use MCU 0.13.0, see PR 12125.

This FSS release contains a breaking change to match the default for expressive on-container colors in MCU 0.12.0. This is also included in the coming bump to MCU 0.13.0 in Flutter after version 3.38.

BREAKING

• The SeedColorScheme.fromSeeds parameter useExpressiveOnContainerColors now defaults to true instead of false.
  • This makes the default behavior of SeedColorScheme.fromSeeds match the default behavior of MCU 0.12.0 and later, where expressive on-container colors are used by default in light mode.
  • If you want to maintain the previous behavior, you can explicitly set useExpressiveOnContainerColors to false when calling SeedColorScheme.fromSeeds.
  • For more information see https://pub.dev/packages/flex_seed_scheme#expressive-on-container-colors
• The DynamicScheme parameter customErrorPalette was renamed to errorPalette to match newly exposed MCU 0.13.0 naming.
  • Previously MCU did not expose this parameter, it was named customErrorPalette in the FSS fork. Now that MCU exposes it, we rename it to match MCU's naming.
  • This is a minor breaking change, you will only hit it if you have used named parameter customErrorPalette in DynamicScheme. It is very unlikely to be used directly by end users of this package, as it is a very low-level API and not used by recommended main public APIs directly, but it was a public API, unfortunately.
  • FlexColorScheme and Themes Playground did not and do not use this API directly, only indirectly via FSS higher APIs.
• Removed already in version 2.0.0 deprecated private int properties in FlexSeedScheme._() and same named public Color parameters in SeedColorScheme.fromSeeds():
  • background
  • onBackground
  • surfaceVariant
• Removed already in version 2.0.0 deprecated public int properties in FlexTones(), FlexTones.light() and FlexTones.dark() and same named parameters in FlexTones.copyWith():
  • backgroundTone
  • onBackgroundTone
  • surfaceVariantTone

CHANGE

• Updated FlexSchemeVariant and their configDetails descriptions to offer better explanations.
  • As stated in the change policy doc comment for the enum FlexSchemeVariant, any changes in the property values variantName, description, configDetails, icon and shade are not considered breaking changes, only patches.
  • These properties may be used when building UIs that present the different scheme variants. They serve no other purpose. They can also be ignored, you can use the enum values as input to build your own UI for selecting and describing the scheme variants. The values are used in the example app and also in the FlexColorScheme package example apps, like the Themes Playground.

CHORE

• MCU: Use MathUtils.sanitizeDegreesDouble for hue calculation in Cam16. (MCU update Nov 19, 2025, not yet in any package version)
• MCU: Added the KeyColor algorithm and its binary search optimization that was added in MCU 0.11.2. This may improve performance when extracting tonal palettes from seed colors.
• MCU: Optimize ARGB and HCT usage in DynamicScheme.
• MCU: A bunch of internal final statics were made const.

TESTS

• Add explicit test for ARGB int representation.
• Improved tests for TonalPalettes.
• Updated test for new useExpressiveOnContainerColors defaulting to true.
• Added loop test for all MCU DynamicSchemeVariants to ensure they can be created without errors, so that same DynamicScheme matches results from Flutter's ColorScheme.fromSeed using corresponding DynamicSchemeVariant. The loop test excludes the variants DynamicSchemeVariant.fidelity, DynamicSchemeVariant.monochrome and DynamicSchemeVariant.content that have their own special tone logic. Previously only the default DynamicSchemeVariant.tonalSpot was tested this way. This test helps us verify that our fork of MCU can match the version of MCU that Flutter uses internally. When Flutter stable changes to use MCU 0.13.0, this test will need to change its flag useExpressiveOnContainerColors from false to true.

Nov 22, 2025

The version requires Flutter 3.38.0 or higher.

This release really brings the bundled forked version of the package Material Color Utilities (MCU) to parity with version 0.13.0. Flutter stable 3.38.x still uses MCU 0.11.1. Next version of Flutter, after stable 0.38, will use MCU 0.13.0, see PR 12125.

This FSS release contains a breaking change to match the default for expressive on-container colors in MCU 0.12.0. This is also included in the coming bump to MCU 0.13.0 in Flutter after version 3.38.

BREAKING

• The SeedColorScheme.fromSeeds parameter useExpressiveOnContainerColors now defaults to true instead of false.
  • This makes the default behavior of SeedColorScheme.fromSeeds match the default behavior of MCU 0.12.0 and later, where expressive on-container colors are used by default in light mode.
  • If you want to maintain the previous behavior, you can explicitly set useExpressiveOnContainerColors to false when calling SeedColorScheme.fromSeeds.
  • For more information see https://pub.dev/packages/flex_seed_scheme#expressive-on-container-colors
• The DynamicScheme parameter customErrorPalette was renamed to errorPalette to match newly exposed MCU 0.13.0 naming.
  • Previously MCU did not expose this parameter, it was named customErrorPalette in the FSS fork. Now that MCU exposes it, we rename it to match MCU's naming.
  • This is a minor breaking change, you will only hit it if you have used named parameter customErrorPalette in DynamicScheme. It is very unlikely to be used directly by end users of this package, as it is a very low-level API and not used by recommended main public APIs directly, but it was a public API, unfortunately.
  • FlexColorScheme and Themes Playground did not and do not use this API directly, only indirectly via FSS higher APIs.
• Removed already in version 2.0.0 deprecated private int properties in FlexSeedScheme._() and same named public Color parameters in SeedColorScheme.fromSeeds():
  • background
  • onBackground
  • surfaceVariant
• Removed already in version 2.0.0 deprecated public int properties in FlexTones(), FlexTones.light() and FlexTones.dark() and same named parameters in FlexTones.copyWith():
  • backgroundTone
  • onBackgroundTone
  • surfaceVariantTone

CHANGE

• Updated FlexSchemeVariant and their configDetails descriptions to offer better explanations.
  • As stated in the change policy doc comment for the enum FlexSchemeVariant, any changes in the property values variantName, description, configDetails, icon and shade are not considered breaking changes, only patches.
  • These properties may be used when building UIs that present the different scheme variants. They serve no other purpose. They can also be ignored, you can use the enum values as input to build your own UI for selecting and describing the scheme variants. The values are used in the example app and also in the FlexColorScheme package example apps, like the Themes Playground.

CHORE

• MCU: Use MathUtils.sanitizeDegreesDouble for hue calculation in Cam16. (MCU update Nov 19, 2025, not yet in any package version)
• MCU: Added the KeyColor algorithm and its binary search optimization that was added in MCU 0.11.2. This may improve performance when extracting tonal palettes from seed colors.
• MCU: Optimize ARGB and HCT usage in DynamicScheme.
• MCU: A bunch of internal final statics were made const.

TESTS

• Add explicit test for ARGB int representation.
• Improved tests for TonalPalettes.
• Updated test for new useExpressiveOnContainerColors defaulting to true.
• Added loop test for all MCU DynamicSchemeVariants to ensure they can be created without errors, so that same DynamicScheme matches results from Flutter's ColorScheme.fromSeed using corresponding DynamicSchemeVariant. The loop test excludes the variants DynamicSchemeVariant.fidelity, DynamicSchemeVariant.monochrome and DynamicSchemeVariant.content that have their own special tone logic. Previously only the default DynamicSchemeVariant.tonalSpot was tested this way. This test helps us verify that our fork of MCU can match the version of MCU that Flutter uses internally. When Flutter stable changes to use MCU 0.13.0, this test will need to change its flag useExpressiveOnContainerColors from false to true.

3.6.1

Nov 5, 2025

FIX

• FIX changelog that dropped the 3.5.1 heading in 3.6.0 release

Nov 5, 2025

FIX

• FIX changelog that dropped the 3.5.1 heading in 3.6.0 release

3.6.0

Requires at least Flutter 3.35.0

Nov 5, 2025

CHORE

• Bump dependencies.
• Update lints to RydMike 2.5.0 lint rules and fix new lint warnings.
• Update the example to support Flutter v3.35.0.
  • Due to breaking changes in Flutter 3.35.0, the package now also requires at least Flutter 3.35.0.
• Update included custom fork of material_color_utilities to include changes in version 0.13.0
  • All of the MaterialDynamicColors fields are now final.
  • NOTE: Flutter stable 3.35.x still uses material_color_utilities 0.11.1, at the time of publishing this, master also does.
  • Since FSS uses its own fork, we can use the latest MCU features without conflicts with the pinned version Flutter uses.

Requires at least Flutter 3.35.0

Nov 5, 2025

CHORE

• Bump dependencies.
• Update lints to RydMike 2.5.0 lint rules and fix new lint warnings.
• Update the example to support Flutter v3.35.0.
  • Due to breaking changes in Flutter 3.35.0, the package now also requires at least Flutter 3.35.0.
• Update included custom fork of material_color_utilities to include changes in version 0.13.0
  • All of the MaterialDynamicColors fields are now final.
  • NOTE: Flutter stable 3.35.x still uses material_color_utilities 0.11.1, at the time of publishing this, master also does.
  • Since FSS uses its own fork, we can use the latest MCU features without conflicts with the pinned version Flutter uses.

3.5.1

March 15, 2025

CHORE

• Update lints for package scoring.
• Minor API documentation updates and fix API doc references.

March 15, 2025

CHORE

• Update lints for package scoring.
• Minor API documentation updates and fix API doc references.

3.5.1-dev.1

March 15, 2025

Version to check if the updates fixes pub score.

CHORE

• Update lints for package scoring.
• Minor API documentation updates and fix API doc references.

3.5.0

Dec 29, 2024

PACKAGE

• Updated the package to support and require at least Flutter v3.27.0.
• Fixed all new analyzer lint warnings and removed usage of all deprecated Color properties.

NEW

• Added convenience Color sRGB extensions that can be used as none deprecated replacements for alpha, red, green, blue and value they are called alpha8bit, red8bit, green8bit, blue8bit and value32bit. FlexSeedScheme uses them internally to avoid using the deprecated Color properties.

Dec 29, 2024

PACKAGE

• Updated the package to support and require at least Flutter v3.27.0.
• Fixed all new analyzer lint warnings and removed usage of all deprecated Color properties.

NEW

• Added convenience Color sRGB extensions that can be used as none deprecated replacements for alpha, red, green, blue and value they are called alpha8bit, red8bit, green8bit, blue8bit and value32bit. FlexSeedScheme uses them internally to avoid using the deprecated Color properties.

3.4.1

Sep 25, 2024

PACKAGE

• No changes to the FlexSeedScheme package

WEB DEMO

• Updated the web demo example to use FlexColorPicker version 3.6.0, where the tonal palette can now also respect monochrome seed colors as its displayed Material tonal palette. This is a new feature in FlexColorPicker 3.6.0.
  • In the updated Web demo, the picker's setting is tied into the demo using the setting respectMonochromeSeed so the picker only uses it when the FlexSeedScheme web demo is configured to do so. The setting for the FlexColorPicker to make monochrome tonal palette for monochrome input and to use chroma of selected color, is a separate feature in the picker, it is not tied to FlexSeedScheme, but for this demo they are linked and use the same settings toggle.

Sep 25, 2024

PACKAGE

• No changes to the FlexSeedScheme package!

WEB DEMO

• Updated the web demo example to use FlexColorPicker version 3.6.0, where the tonal palette can now also respect monochrome seed colors as its displayed Material tonal palette. This is a new feature in FlexColorPicker 3.6.0.
  • In the updated Web demo, the picker's setting is tied into the demo using the setting respectMonochromeSeed so the picker only uses it when the FlexSeedScheme web demo is configured to do so. The setting for the FlexColorPicker to make monochrome tonal palette for monochrome input and to use chroma of selected color, is a separate feature in the picker, it is not tied to FlexSeedScheme, but for this demo they are linked and use the same settings toggle.

Sep 23, 2024

CHANGE

• The parameter useExpressiveOnContainerColors in SeedColorScheme.fromSeeds now works with a scheme variant regardless of if it has isFlutterScheme set to true or false. Meaning it impacts both MCU DynamicSchemeVariant and FSS FlexTones based scheme variants.

  • For FlexTones based variants, when using a built-in FlexTones or even a custom one, it is no longer necessary to use the FlexTones modifier .expressiveOnContainer() on the used tones to get a seeded color scheme with expressive on container tones in light mode.
  • The FlexTones based modifier .expressiveOnContainer() is still used, but it is applied internally when the flag useExpressiveOnContainerColors is set to true.
  • The useExpressiveOnContainerColors only applies in light mode to on container tones that are equal to 10, other tones are considered custom on purpose and are not changed. This is in-line with that the MCU DynamicSchemeVariants that did not use tone 30 before as on container color in light mode, like Fidelity, Monochrome and Content were not affected by this change in MCU 0.12.0. In the same manner, this flag no longer changes FlexTones based schemes that have on container tones that are not 10. This applies to some on container colors in UltraContrast, Candy Pop and Chroma predefined FlexTones.
  • This change makes this flag consistent and applicable to all seed generated schemes, regardless of if it is based on DynamicSchemeVariant, built-in FlexTones or even custom FlexTones configurations.
  • For MCU seed generated schemes, useExpressiveOnContainerColors only has any impact when contrast level is at the default value (0), normal contrast.
  • When using FFS seed generated schemes with useExpressiveOnContainerColors set to true, the modifier is applied before any FlexTones modifiers. Using tones modifiers, like e.g. onMainsUseBW() will thus as expected, override this setting and set on container colors to tone 0 or tone 100, depending on the container colors brightness.

NEW

• A new bool parameter, respectMonochromeSeed in SeedColorScheme.fromSeeds can now be used to make seed generated ColorSchemes that work as expected if a monochrome color is used as seed color input.
  • When set to true, any monochrome RGB input value will result in the creation of a greyscale tonal palette for the palette using the monochrome seed color. An RGB monochrome value is one where Red, Green and Blue values are all equal.
  • Previously in FSS and in Material Color Utilities (MCU) and thus still as default in Flutter ColorScheme.fromSeed, using a monochrome seed color value or white, resulted in a tonal palette with cyan color tones. A black input resulted in red like color tones. This is not very intuitive and not really expected when using monochrome seed colors.
  • FSS still defaults to setting respectMonochromeSeed to false, to not break any existing code that may rely on the old behavior.
  • Prefer setting respectMonochromeSeed to true, to get more logical seed results when using monochrome seed colors or white and black as seed colors.
  • NOTE: When using respectMonochromeSeed with DynamicSchemeVariant variants fidelity or content, for some monochrome input colors they produce primaryContainer and onPrimaryContainer as well as tertiaryContainer and onTertiaryContainer color pairs, with low contrast. Consider using some other scheme variants with monochrome seed colors. All others work well with any monochrome seed color. This is just how the MCU DynamicSchemes SchemeContent and SchemeFidelity are defined in MCU. They also produce fairly low contrast for these color pairs with very dark seed colors. This behavior with MCU's SchemeContent and SchemeFidelity could be fixed in FlexSeedScheme's internal MCU fork, but we want to keep the result of these schemes consistent with MCU.

Sep 7, 2024

NEW

• Exposed DynamicColor, MaterialDynamicColors and Scheme from the underlying forked Material Color Utilities (MCU) library.
• Un-deprecated Scheme, that original MCU deprecated. It does not conflict with the new DynamicSchemes that replaced it, thus in the internal MCU fork, we do not need to deprecate it and can offer it for legacy access to old ColorScheme.fromSeed scheme result in use before Flutter 3.22.0.
  • Internally FlexSeedScheme does not use Scheme for its own legacy version of the same scheme, it uses its FlexTones based setup instead, but produces the same color values. We still recommend using its tones FlexTones.material3Legacy version instead of Scheme for a legacy Material-3 seed generated ColorScheme.
  • This API is provided for legacy access to the old MCU Scheme style and API, that was used in Flutter 3.19.0 and earlier in its ColorScheme.fromSeed constructor back then. If you want to recreate its exact older internal API algorithm, you can now do so using Scheme that it used to use before Flutter 3.22.0.
  • This revived Scheme class was also complemented with the new ColorScheme colors added in Flutter 3.22.0, but it uses legacy Flutter 3.19 and earlier tone mappings for all colors that existed then. Except for dark mode onErrorContainer that it corrected from 80 to 90. It was always a bug in Flutter version 3.19 and earlier that tone 80 was used.

Aug 27, 2024

CHANGE

• The FlexPaletteType.extended tones got three new tones, tones 65, 75 and 84. It now has 30 tones.

NEW

• The tones configuration class FlexTones got a new modifier, higherContrastFixed(). It can be applied to any predefined or custom FlexTones to make a returned FlexTones instance where the tones for the fixed colors fixed, onFixed, fixedDim and onFixedVariant are set to 92, 6, 84 and 12 instead of their Material-3 specification tones 90, 10, 80 and 30. This for an alternative set of fixed colors with more contrast.

July 23, 2024

FIX

• FIX the faulty tones for the modified FlexTones.vividSurfaces surface tones. They were in version 3.1.0 set to 96 for a light scheme and 10 for a dark scheme. The values need to be 98 and 6 to not clash with any other important tones used by all the surface colors and provide separation to them. Tones 98 and 6 are also the default tones in M3 design for them, there is very little wiggle room here.

• FIX tone for the modified FlexTones.vividBackground it was in version 3.1.0 set to 97 for its light scheme, it needs to use value 100 (white) to really provide a "vivid" background mode in light mode and offer some differentiation to FlexTones.vividSurfaces in light mode. In dark mode it still uses tone 5, which is already different and darker than 6 used by FlexTones.vividSurfaces.

INFO

• How to use legacy FlexTones.vividSurfaces and FlexTones.vividBackground tone mappings?
  • FSS version 3.1.0 removed the deprecated colors background, onBackground and surfaceVariant from being defined as a part of the SeedColorScheme.fromSeeds result. They still get color values, but they are whatever the default values the default Flutter SDK ColorScheme() constructor gives them. These colors were deprecated in Flutter 3.22.0 and are now removed from being defined and accessed by FSS.
  • FSS 3.1.0 also changed the tone mappings for FlexTones.vividSurfaces and FlexTones.vividBackground to make them have some distinguishing differences when background color no longer has any effect or usage, and also to adhere to new the ColorScheme design intent.
  • You should prefer to map one of the new surface colors that are already of a shade close to old surface and background colors, to theme colors as needed by your design. There are eight different surface shades to choose from in the ColorScheme introduced in Flutter 3.22, compared to three before.
  • If you really need the pre-Flutter 3.22 legacy style for FlexTones.vividSurfaces or FlexTones.vividBackground you can optionally recreate them with copyWith on their definitions like this:

// For light legacy FlexTones.vividSurfaces 
final ColorScheme vividSurfacesLight = SeedColorScheme.fromSeeds(
    brightness: Brightness.light,
    primaryKey: mySeedColor,
    tones: FlexTones.vividSurfaces(Brightness.light).copyWith(surfaceTone: 95),
  );
// For dark legacy FlexTones.vividSurfaces 
final ColorScheme vividSurfacesDark = SeedColorScheme.fromSeeds(
    brightness: Brightness.dark,
    primaryKey: mySeedColor,
    tones: FlexTones.vividSurfaces(Brightness.dark).copyWith(surfaceTone: 20),
  );

// For light legacy FlexTones.vividBackground 
final ColorScheme vividBackgroundLight = SeedColorScheme.fromSeeds(
  brightness: Brightness.light,
  primaryKey: mySeedColor,
  tones: FlexTones.vividBackground(Brightness.light).copyWith(surfaceTone: 98),
);
// For dark legacy FlexTones.vividBackground 
final ColorScheme vividBackgroundDark = SeedColorScheme.fromSeeds(
  brightness: Brightness.dark,
  primaryKey: mySeedColor,
  tones: FlexTones.vividBackground(Brightness.dark).copyWith(surfaceTone: 6),
);

July 13, 2024

CHORE

• FIX the pub score.
• Update readme.

July 12, 2024

CHORE

• Experiment to find and remove references from the package to deprecated properties for scoring purposes. The deprecated colors are NOT used anymore, but pub's pana analyzer still complains. It happily ignores the "allow usage of self-deprecated members" setting. It also complains about references used in doc comments. This is the first attempt to find and fix all things it complains about.

July 12, 2024

CHANGE

• Removes the in Flutter 3.22.0 deprecated ColorScheme colors background, onBackground and surfaceVariant from being defined as a part of the SeedColorScheme.fromSeeds result. They still get color values, but they are whatever the default values the default Flutter SDK ColorScheme() constructor gives them. These colors were deprecated in Flutter 3.22.0 and are now removed from being defined and accessed by FSS.

  • The removal is done to keep FSS in sync with Flutter SDK and to avoid using deprecated colors.
  • These colors should in application usage be replaced by surface, onSurface and surfaceContainerLowest in Flutter 3.22.0 and later.
    • If you for some reason in Flutter 3.22.0 and later still need the deprecated colors, use FSS version 3.0.0.

• To make FlexTones.vividSurfaces and FlexTones.vividBackground have some distinguishing differences when background color no longer has any effect or usage, the following changes were made to their tone mappings:

  • FlexTones.vividSurfaces:
    • Light: surfaceTone 95 -> 96,
    • Dark: surfaceTone 20 -> 10.
  • FlexTones.vividBackground:
    • Light: surfaceTone 98 -> 97,
    • Dark: surfaceTone 6 -> 5.

• How to use legacy FlexTones.vividSurfaces and FlexTones.vividBackground tone mappings?

  • You should prefer to map one of the new surface colors that are already of a shade close to old surface and background colors, to theme colors as needed by your design. There are eight different surface shades to choose from in the ColorScheme introduced in Flutter 3.22, compared to three before.
  • If you really need the pre-Flutter 3.22 legacy style for FlexTones.vividSurfaces or FlexTones.vividBackground you can optionally recreate them with copyWith on their definitions like this:

// For light legacy FlexTones.vividSurfaces 
final ColorScheme vividSurfacesLight = SeedColorScheme.fromSeeds(
    brightness: Brightness.light,
    primaryKey: mySeedColor,
    tones: FlexTones.vividSurfaces(Brightness.light).copyWith(surfaceTone: 95),
  );
// For dark legacy FlexTones.vividSurfaces 
final ColorScheme vividSurfacesDark = SeedColorScheme.fromSeeds(
    brightness: Brightness.dark,
    primaryKey: mySeedColor,
    tones: FlexTones.vividSurfaces(Brightness.dark).copyWith(surfaceTone: 20),
  );

// For light legacy FlexTones.vividBackground 
final ColorScheme vividBackgroundLight = SeedColorScheme.fromSeeds(
  brightness: Brightness.light,
  primaryKey: mySeedColor,
  tones: FlexTones.vividBackground(Brightness.light).copyWith(surfaceTone: 98),
);
// For dark legacy FlexTones.vividBackground 
final ColorScheme vividBackgroundDark = SeedColorScheme.fromSeeds(
  brightness: Brightness.dark,
  primaryKey: mySeedColor,
  tones: FlexTones.vividBackground(Brightness.dark).copyWith(surfaceTone: 6),
);

CHORE

• Update all_lint_rules.yaml.

EXAMPLE

• Remove showing the deprecated colors background, onBackground and surfaceVariant in the example app.

June 24, 2024

Bring the bundled forked version of the package Material Color Utilities (MCU) to feature parity with version 0.12.0 of the original package. The internal fork for the first time nw also adds features and capabilities that do not exist in the original package. Previously FSS only bundled MCU to avoid version conflicts with Flutter SDK when using different channels. Different Flutter channels typically pin incompatible versions of MCU.

The bundled forked version of MCU also has more tests than the original, allowing us to detect when any new MCU version "silently" changes color results it produced in the past.

• BREAKING

  • The API for SeedColorScheme.buildDynamicScheme was changed to enable support for multiple seed colors on the MCU based DynamicScheme APIs and its extended schemes. For most normal use cases, you will not notice this, as it is quite a low-level API in FSS that end users normally do not use.

• NEW

  • The forked internal MCU version received new features. The DynamicScheme can now accept an optional customErrorPalette and then SchemeTonalSpot, SchemeContent, SchemeFidelity, SchemeExpressive, SchemeFruitSalad, SchemeMonochrome, SchemeNeutral, SchemeRainbow and SchemeVibrant that extend DynamicScheme all received properties to support individual seed colors for all tonal palettes.

  • The above addition enables SeedColorScheme.fromSeeds to support using all its key seed colors also when using MCU based DynamicScheme variants and not just for FlexTones based tones and variants. When using key seed colors with MCU variants, they still respect their original design intent.

  • Added support for contrastLevel to SeedColorScheme.fromSeeds. This allows you to set the desired contrast level of the generated color scheme when using SeedColorScheme.fromSeeds with the variant property, for variants that are based on MCU's DynamicScheme. Such variants have their isFlutterScheme set to true.

    • The contrastLevel parameter indicates the contrast level between color pairs, such as primary and onPrimary.The value 0.0 is the default (normal); -1.0 is the lowest; 1.0 is the highest. From Material Design guideline, the medium and high-contrast levels correspond to 0.5 and 1.0 respectively.
    • The contrastLevel in Flutter SDK is not yet available in ColorScheme.fromSeed in Flutter stable 3.22.x, but is available on the master channel 3.23.x. With FSS you can use it already in Flutter 3.22.x.
    • NOTE: Using contrastLevel has no effect when using tones. However, with tones you can create custom tones with even more flexibility in seed generation to make schemes with higher or less contrast. Two pre-configured high contrast tones exist earlier via FlexTones.highContrast and FlexTones.ultraContrast.

  • Updated MaterialDynamicColors to optionally use the new Material expressive on-colors spec for none surface on-container colors. This feature is not on by default. You can opt in on this new standard by setting useExpressiveOnContainerColors to true in SeedColorScheme.fromSeeds.

    • This option is only available when using MCU based DynamicScheme variants and not when using FlexTones based tones and variants, plus it only applies to variants that are based on MCU's DynamicScheme. Such variants have their isFlutterScheme set to true.
    • Opting in changes the light mode color tone for the colors onPrimaryContainer, onSecondaryContainer, onTertiaryContainer and onErrorContainer from 10 to 30 making them more color expressive, but they also have less contrast.
    • The accepted min contrast curve is thus now ContrastCurve(3, 4.5, 7, 11) instead of ContrastCurve(4.5, 7, 11, 21) for the on-container colors. Meaning normal contrast of 4.5 is now accepted when it was 7 before.
    • Prior to MCU version 0.12.0 the MaterialDynamicColors used an older M3 spec. Flutter stable 3.22.x and Flutter master 3.23.x still use MCU versions lower than 0.12.0 and default to the older color tones 10 in light mode. This will be changed in Flutter SDK when Flutter is updated to use MCU 0.12.0 or later. With FSS 3.0.0, you can opt in on using the new spec already now. But FSS still also defaults to the older spec with more contrast. When Flutter stable changes to use the new spec, FSS will also change to use it as default. While Flutter and MCU will then no longer offer the older higher contrast version, FSS will continue to do so.
    • The optional usage of the expressive colors for on-container colors is also a customization of MCU features in the forked version. We see value in being able to offer both the higher contrast older version and the new more color expressive one.

  • The tones configuration class FlexTones got a new built-in modifier, monochromeSurfaces(). It can be applied to any predefined or custom FlexTones to make the surface colors monochrome and use pure greyscale for the neutral and neutral variant tonal palettes, with no color tint from their key color or primary key seed color.

  • The tones configuration class FlexTones also got the new modifier, expressiveOnContainer(). It can be applied to any predefined or custom FlexTones to make a returned FlexTones instance where the tones for light mode on container tones are set to 30 for more color expressive container text and icons on none surface containers.

    • This modifier only impacts none surface on-container tones that are dark and thus only has any impact on the light theme mode on-container colors.
    • The impacted on container colors are onPrimaryContainerTone,onSecondaryContainerTone, onTertiaryContainerTone and onErrorContainerTone.
    • This feature brings optional light mode expressive on-container colors to any predefined or custom FlexTones configuration. The expressive on-color in light mode containers are a new change to Material Design 3 ColorScheme. It was introduced in Material Color Utilities (MCU) package v0.12.0.
    • This modifier is equivalent to setting the SeedColorScheme.fromSeeds and its useExpressiveOnContainerColors to true when using MCU dynamic scheme variant based seeded color schemes.

• COLOR VALUE STYLE BREAKING

  • Changed FlexTones.chroma tone secondaryTone from 60 to 50 in light mode for better chroma fidelity when using FlexTone.chroma in light mode.

• CHANGE

  • Revert Flutter constraint back to >=3.22.0 from >=3.22.0-0.3.pre that was only used by FSS dev release 2.1.0-dev.1. Since beta and master are now on 3.23.0 or higher versions, the >=3.22.0 constraint can now be used by master and beta channels without any issue.
  • Improved the descriptions and config info strings of FlexSchemeVariant enum values.
  • The EXAMPLE APP was extensively revised to include support for all the new features and to also show some old features not demonstrated before.

• FIX

  • The FlexTones.material3Legacy was corrected. It had some incorrect tones and chroma in its configuration. The mistakes were fixed. Tests were added to check the FlexTones.material3Legacy compared to the MCU deprecated Scheme-based colors, for colors that exist in both.
  • EXAMPLE APP: The key color to seed the error palette was not used in the main example in dark mode.

May 21, 2024

This is a temp pre-release of FFS 2.1.0.

FIX

• FIX #13. Sets Flutter version constraint to flutter: >=3.22.0-0.3.pre, so that the package can also be used on beta and stable channels, while they are still on 3.22.0-a.b.pre versions, which is considered smaller than 3.22.0, used in the stable release of the package. You can use this version of the package if you need to use beta or master channel before they have been bumped to 3.23.x. This release is apart from the version constraint difference identical to the 2.0.0 release.

May 14, 2024

This release adds support for the revised Material-3 ColorScheme released in Flutter version 3.22.0 and for seeded scheme variants, that will arrive in the Flutter stable release after 3.22.x.

• CHANGE

  • Bring the internal Material Color Utilities (MCU) library version to parity with its latest package release 0.11.1. Flutter SDK stable 3.22 still uses MCU 0.8.0, but the Flutter master channel already uses MCU 0.11.1.
  • The FlexPaletteType.extended tones got two new tones added, tone 2, and 24. It now has 27 tones.

• NEW

  • Support revised Material-3 ColorScheme with the new colors primaryFixed, primaryFixedDim, onPrimaryFixed, onPrimaryFixedVariant, secondaryFixed, secondaryFixedDim, onSecondaryFixed, onSecondaryFixedVariant, tertiaryFixed, tertiaryFixedDim, onTertiaryFixed, onTertiaryFixedVariant, surfaceDim, surfaceBright, surfaceContainerLowest, surfaceContainerLow, surfaceContainer, surfaceContainerHigh and surfaceContainerHighest.

  • New alternative way to specify the used seeding algorithm in SeedColorScheme.fromSeeds by providing new enum value FlexSchemeVariant to its variant property.

    • In addition to supporting selection of built-in FlexTones, the variant property also supports using Flutter SDK, MCU based scheme variants tonalSpot, monochrome, neutral, vibrant, expressive, content,rainbow and fruitSalad in by specifying them in property variant in SeedColorScheme.fromSeeds. In Flutter 3.22 only the default tonalSpot is available, but with FSS you can use any of the other variants as well already in Flutter 3.22. The other variants are not yet available in Flutter 3.22, but they are available in the ColorScheme API in the master channel and will be available in Flutter ColorScheme.fromSeed in the next stable release after 3.22. With FSS you can use them already starting from Flutter 3.22.0.
    • With the variants enum property you can also select built-in FlexTones that you could use before in SeedColorScheme.fromSeeds in tones. The FlexTones are still available and can be used as before, it has some advantages. With tones you can create customized seed extractions based on FlexTones and you can use tones surface quick modifiers, onMainsUseBW, onSurfacesUseBW and surfacesUseBW.
    • When using variants, if the variant is one of the Flutter SDK/MCU variants, it will not use more than one key color, the primary as seed color. The FlexSchemeVariant that have their property isFlutterScheme set to true are part of the Flutter SDK/MCU variants.
    • The Flutter SDK/MCU variants are tonalSpot, fidelity, monochrome, neutral, vibrant, expressive, content, rainbow and fruitSalad.
    • The other FlexSchemeVariant that have their property isFlutterScheme set to false are part of the FlexTones variants using the corresponding built-in FlexTones as seed extraction. The variants are material, material3Legacy, soft, vivid, vividSurfaces, highContrast, ultraContrast, jolly, vividBackground, oneHue, candyPop and chroma. The chroma option is similar to the new nice SDK/MCU one called fidelity, in that it follows chroma of seed color, with the added benefit that it can use a separate seed color for each tonal palette.
    • The APIs variant and tones are mutually exclusive, you can only use one of them in SeedColorScheme.fromSeeds. Both can be unspecified, but if you specify one, the other must be unspecified/null.

• A new FlexTones.material3Legacy was added. This FlexTones configuration preserves and provides access to the seed generation used by Flutter prior to Flutter version 3.22 and as used by FlexTones.materialin FlexSeedScheme before version 2.0.0. If you in Flutter 3.22 and FlexSeedScheme 2.0.0 need to replicate this style you can use this FlexTones in SeedColorScheme.fromSeeds property tones or the FlexSchemeVariant.material3Legacy in variants.

• BREAKING

  • The Material-3 ColorScheme colors background, onBackground and surfaceVariant have been deprecated since they are also deprecated in Flutter 3.22.
    • These deprecated colors are still supported in SeedColorScheme.fromSeeds and FlexTones, but they will be removed in a future release. They are replaced by surface, onSurface and surfaceContainerLowest. There are also many new surface colors, like surfaceDim, surfaceBright and surfaceContainerLowest in the new Material-3 ColorScheme in Flutter 3.22.
    • The fact that these deprecated colors are still referenced in the package will reduce its pub.dev score with 10 points, but they are kept for now to maintain FULL compatibility with Flutter 3.22 that also still provides values for these deprecated colors and uses them in code. This package needs to provide the same values to be fully compatible. The ColorScheme colors background, onBackground and surfaceVariant may only be fully removed when they have been removed from the Flutter SDK stable channel. If later tests show they can be removed without breaking any styles earlier, they will be removed in a future release of this package, even if they are still available in the Flutter SDK stable channel. A future dev version may also remove them to provide compatibility with the Flutter master channel when they are removed there.

• BREAKING STYLES

  • All built-in FlexTones now use the paletteType extended via FlexPaletteType.extended as default for additional tone fidelity. This is used for compatibility with Flutter 3.22 and its revised ColorScheme.

  • The default tones for the built-in FlexTones have been adjusted to match the new Material-3 ColorScheme in Flutter 3.22. The new tones and default styles are marginally different but also better than in previous Flutter versions. If you need the result and style used in Flutter 3.19 and earlier, you can use the FlexTones.material3Legacy as tones in SeedColorScheme.fromSeeds to get the result FlexTones.material produced in FSS before version 2.0.0 and that was also the default in Flutter in version 3.19 and earlier.

  • The FlexSchemeVariant.tonalSpot is the variant that Flutter SDK uses from MCU in ColorScheme.fromSeed in Flutter 3.22 and later when you make seed generated color schemes with it. This generated scheme is different from the one ColorScheme.fromSeed generated in Flutter 3.19 and earlier. If you need the result and style used in Flutter 3.19 and earlier, you can use the material3Legacy as tones or variant in SeedColorScheme.fromSeeds to get the result FlexTones.material produced in FSS before version 2.0.0 and that was also the default in Flutter in version 3.19 and earlier when using ColorScheme.fromSeed.

  • The FlexTones.material has been updated and now produces the same result as tonalSpot in tests. There may be some edge cases where there are rounding differences. The material alternative can be used both in variant and tones. It provides the advantages over tonalSpot that since it is a FlexTones, it can use multiple seed colors and if used in tones, its results can be quick adjusted with onMainsUseBW, onSurfacesUseBW and surfacesUseBW. The tonalSpot is a Flutter SDK/MCU variant and does not support these customizations.

April 3, 2024

• NEW
  • Exposed Hct and ViewingConditions from the underlying Material Color Utilities (MCU) library. They are exposed for convenience, you no longer have to add and import (MCU) to use them.
  • Add CODE_OF_CONDUCT.md and CONTRIBUTING.md files for guidance on contributing to the package.

July 2, 2023

• NEW

  • Added support for new HCT tones used by updated Material3 color system, that were added during the first half of 2023 to the Material 3 color system specification. The added tones 4, 6, 12, 17, 22 are for new dark mode surfaces in revised Material 3 dark surface colors. Likewise, added tones 97, 96, 94, 92, 87 are for light mode surfaces in the updated Material 3 color system. For more information, see: https://m3.material.io/styles/color/the-color-system/color-roles.
    • The change and additions are none breaking. APIs that want and can use the extended tones can pass in an optional paletteType of FlexPaletteType and set it to FlexPaletteType.extended, by default its values FlexPaletteType.common resulting in the 15 tones [0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 98, 99, 100] being produced as before.
    • The complete list of the 25 extended tones are [0, 4, 5, 6, 10, 12, 17, 20, 22, 30, 40, 50, 60, 70, 80, 87, 90, 92, 94, 95, 96, 97, 98, 99, 100].
    • None breaking Changed APIs that now support using paletteType of FlexPaletteTypeare:
      • FlexTonalPalette.of
      • FlexTonalPalette.fromList
      • FlexCorePalette.of
      • FlexCorePalette.fromHueChroma
      • FlexCorePalette.fromList
      • FlexCorePalette.fromSeeds
      • FlexTones
    • Flutter 3.10 and earlier do not yet use these new tones in its standard ColorScheme, but since they are in the Material 3 spec, they will arrive at some later point.
    • FlexTonalPalette, like MCU TonalPalette, caps chroma for tones higher than or equal to 90, to maximum chroma value of 40. In FlexTonalPalette this still applies when using FlexPaletteType.common, when you use the FlexPaletteType.extended, there is no chroma max cap on high tones, it uses fidelity mode for high tones. When using type FlexPaletteType.common the chroma of high tones (>= 90), is limited to maximum 40. This keeps the chromacity of tones 90 to 100, lower than 40. If the source uses has more chromacity than 40, there may be a sudden jump in chroma reduction at tone 90. This is the standard behavior for the original Material-3 tonal palette computation. The FlexPaletteType.common type is intended to be used when there is a need to follow strict M3's original palette design.
    • When using the FlexPaletteType.extended type tones, there are not only the new tones, but the chroma limit of tones >= 90 is also removed. This increases fidelity of higher tone when high chromacity is used.
  • Added two new pre-configured FlexToness, candyPop and chroma, they use the new FlexPaletteType.extended tonal palette.
  • Added new FlexTones modifier surfacesUseBW(). It can be used as a modifier to force any FlexTones seed strategy to use tone 100 (white) or tone 0 (black) as background and surface colors, depending on if they are dark or light

• CHANGE

  • Minor style breaking: To correct and improve produced themes, the tones primaryContainerTone and secondaryContainerTone for light mode FlexTones.highContrast and FlexTones.ultraContrast were both changed from 95 to 90. This produces brighter and more punchy themes for these two high-contrast themes in light mode.

• CHORE

  • Bump Dart SDK to >= 3.0.0 and Flutter SDK to >= 3.10.0. Fix lints for the bump.
  • Add all Material Color Utilities (MCU) updates from its Dart version to the internal bundled version.
    • This includes all PRs up to and including "PR: 28.6.2023 Change var back to double in Java." This equals Dart version 0.8.0 published on June 29, 2023, with its two new schemes fruit salad and rainbow.
    • At this time, Flutter master was using MCU version 0.5.0 and Flutter stable 3.10.0 still used the MCU version 0.2.0.
    • Since MCU is using zero semver and Flutter SDK, depends on it, any minor version number change is breaking and cannot be resolved across Flutter channels if a package also uses MCU. This is the reason why (FSS) for now does not use MCU directly. It bundles its own version of it for now. This also means FSS may sometimes use a newer version of MCU than Flutter stable, beta, and master. FSS may stop bundling MCU when it stops getting so many frequent breaking updates that cause dependency hell for a package that needs to depend on MCU and work on all Flutter channels.

• EXAMPLE

  • Major refactoring of the example app.
  • Use a theme controller and ListenableBuilder to rebuild the app theme when the theme controller changes.
  • Feature: Add showing generated tonal palettes to the example.
  • Feature: Separate controls for making on Main and on Surface colors black and white.
  • Feature: Change seed colors in the app with Color picker.
  • Feature: Add switching between showing common tones and extended tones.
  • Feature: Add selecting a custom color as key color for error palette.

May 11, 2023

INTERNAL CHANGE

• Removed the Material Color Utilities (MCU) dependency.

  • It is now included and maintained as a separate forked code base in FSS, while keeping MCU's original license in place for its parts. The included MCU library was only modified to abide by the much stricter lint rules used in FSS. More unit tests for better test coverage of MCU were added as well.

  • Why is MCU included as a forked version baked into FSS?

    The constant changes in MCU, with e.g., recent three different breaking-pinned zero-ver versions used in Flutter stable, beta and master channels, made it hopeless to depend on MCU. Using it caused repeated version conflicts with Flutter's own pinned dependency on different breaking versions of it, in different Flutter channels. FSS needs to be able to work across all Flutter channels without constant hassle caused by MCU and which exact version of it different version of Flutter repo itself is pinned to.

  • The included forked version will be kept in sync with the original and updated when needed. Currently included MCU version is 0.5.0, the latest one, which is what Flutter master channel currently uses. However, new Flutter stable 3.10 is still using MCU 0.2.0. If the MCU package stabilizes and improves its constant breaking changes, FSS may later again be changed to depend on the original package. Until then, it embeds the code for it in its package to avoid the version conflict hassles it has repeatedly caused. These changes are all internal to the FSS package and do not affect how it works.

NEW

• Exposed Blend, CorePalette and TonalPalette from MCU. Previously only Cam16 was exposed. These APIs from MCU are exposed because FlexColorScheme (FCS) uses them. By exposing these APIs from the included MCU in FSS, it also no longer has any dependency on the MCU package that Flutter depends on. This makes it easier for the latest release of FCS to also work on all current Flutter channels.

Future versions of FSS may expose a few more APIs from MCU, but more likely it will offer a few new alternative ones with its own twist. Like it is for example, doing with SeedColorScheme.fromSeeds.

Apr 16, 2023

• Bumped Flutter sdk version constraint to >=2.19.0 <4.0.0 (from >=2.18.0 <3.0.0)
• Changed material_color_utilities version constraint to >=0.2.0 <0.4.0 from ^0.2.0.

These changes enable the package to be used on current Flutter stable 3.7 versions, as well as the latest 3.10.x versions on channels beta and master. It will also work with the next stable Flutter release after 3.7.

Mar 19, 2023

• FIX: Version 1.2.0 unintentionally introduced a lower level breaking API from version 1.1.0. This release relaxes the API and fixes the breakage.

Jan 30, 2023

• Add example screenshots to pubspec.yaml.

Jan 25, 2023

• Fix date on 1.2.0 changelog.

Jan 25, 2023

Requires minimum Flutter 3.7.0. Now support outlineVariant and scrim colors in ColorScheme in Flutter stable 3.7.0 and later.

This release also adds new features to allow customization of seed generation of error, neutral and neutral variant tonal palettes. All listed features are unchanged from the previous dev pre-release 1.2.0-dev.1.

NEW

• Adds support for outlineVariant and scrim colors in ColorScheme.

• Added support for customizing seed generation for error, neutral and neutral variant tonal palettes.

• To support the new features the SeedColorScheme.fromSeeds got the following new Color properties errorKey, neutralKey and neutralVariantKey.

• The FlexTones class got the following new double properties errorChroma, errorMinChroma, neutralMinChroma and neutralVariantMinChroma

• The FlexCorePalette.fromSeeds factory got the following new int properties error, neutral, neutralVariant and neutralVariantMinChroma. As well as new double properties errorChroma, errorMinChroma, neutralChroma, neutralMinChroma, neutralVariantChroma and neutralVariantMinChroma.

• The demo application got an About dialog. The demo app also shows the ColorScheme applied on common Material components.

Dec 23, 2022

Requires minimum Flutter 3.7.0-1.2.pre (beta channel). This is a development pre-release to support outlineVariant and scrim colors in ColorScheme. It is used for development and testing against new Material 3 features in Flutter 3.7 beta and master channel. It will be released as a stable version when the new color properties land in the Flutter stable channel, most likely after January 25, 2023.

The release also adds new features to allow customization of seed generation of error, neutral and neutral variant tonal palettes.

NEW

• Adds support for outlineVariant and scrim colors in ColorScheme.

• Added support for customizing seed generation for error, neutral and neutral variant tonal palettes.

• To support the new features the SeedColorScheme.fromSeeds got the following new Color properties errorKey, neutralKey and neutralVariantKey.

• The FlexTones class got the following new double properties errorChroma, errorMinChroma, neutralMinChroma and neutralVariantMinChroma

• The FlexCorePalette.fromSeeds factory got the following new int properties error, neutral, neutralVariant and neutralVariantMinChroma. As well as new double properties errorChroma, errorMinChroma, neutralChroma, neutralMinChroma, neutralVariantChroma and neutralVariantMinChroma.

• The demo application got an About dialog. The demo app also shows the ColorScheme applied on common Material components.

Nov 17, 2022

NEW

• Added new FlexTones method onMainsUseBW, that can return a new instance of its configurations with tone mapping for its main *on colors set to tone, 0 (black) or 100 (white), depending on what is appropriate for its main color tones. The main colors are primary, secondary, tertiary, error and their containers. The method works on any configured FlexTones, also custom ones, not only the built-in ones.

• Added new FlexTones method onSurfacesUseBW, that can return a new instance of its configurations with tone mapping for its surface *on colors set to tone, 0 (black) or 100 (white), depending on what is appropriate for its surface color tones. Surface colors are background, surface, surfaceVariant and inverseSurface. The method works on any configured FlexTones, also custom ones, not only the built-in ones.

• To be able to support creating mono-hue seeded color schemes, the FlexCorePalette.fromSeeds got a new property tertiaryHueRotation. It controls the used hue rotation degrees from primary key color, that is used when a tertiary seed key color is not provided. The tertiaryHueRotation defaults 60 degrees, same as previously from Material 3 color system hard-coded value.

• Added two new FlexTones.

  • FlexTones.oneHue that set tertiaryHueRotation to 0, so we can create a mono hue palette if we only provide primary key color as seed.
  • FlexTones.vividBackground that is a copy of FlexTones.vividSurfaces but with tone mapping for background and surface swapped.

CHANGE

Tone mappings for some pre-configured FlexTones were slightly modified. They now produce improved and more usable color schemes. Most significantly, the mappings for FlexTones.vividSurfaces were modified to provide a more usable and improved vivid surfaces tinted color scheme, while still offering a slightly more tinted surface design than FlexTones.vivid. Tone mapping changes are as follows:

• The FlexTones.vivid, brightness light:
  • Tone surfaceTone was changed from 99 to 98.
• The FlexTones.vivid, brightness dark:
  • Tone onErrorContainerTone was changed from 90 to 80 (dark M3 default).
  • Tone backgroundTone was changed from 10 to 5.
• The FlexTones.vividSurfaces brightness light:
  • Tone onPrimaryTone was changed from 95 to 98.
  • Tone onSecondaryTone was changed from 95 to 98.
  • Tone onTertiaryTone was changed from 95 to 98.
  • Tone onErrorTone was changed from 95 to 98.
  • Tone primaryContainerTone was changed from 80 to 90 (light M3 default).
  • Tone secondaryContainerTone was changed from 80 to 90 (light M3 default).
  • Tone tertiaryContainerTone was changed from 80 to 90 (light M3 default).
  • Tone errorContainerTone was changed from 80 to 90 (light M3 default).
  • Tone surfaceVariantTone was changed from 80 to 90 (light M3 default).
  • Tone backgroundTone was changed from 90 to 98.
  • neutralChroma was changed from 8 to 5.
  • neutralVariantChroma was changed from 16 to 10.
• The FlexTones.vividSurfaces brightness dark:
  • Tone primaryContainerTone was changed from 40 to 20.
  • Tone tertiaryContainerTone was changed from 40 to 30 (dark M3 default).
  • Tone primaryContainerTone was changed from 40 to 30 (dark M3 default).
  • Tone onErrorTone was changed from 20 to 30 (dark M3 default).
  • Tone onErrorContainerTone was changed from 90 to 80 (dark M3 default).
  • Tone surfaceTone was changed from 10 to 20.
  • Tone surfaceVariantTone was changed from 40 to 30 (dark M3 default).
  • Tone backgroundTone was changed from 20 to 10.
  • Tone onSurfaceVariantTone was changed from 90 to 95.
  • Tone onInverseSurfaceTone was changed from 30 to 20 (dark M3 default).
  • neutralChroma was changed from 8 to 5.
  • neutralVariantChroma was changed from 16 to 10.
• The FlexTones.ultraContrast brightness light:
  • Tone primaryTone was changed from 30 to 20.
• The FlexTones.ultraContrast brightness dark:
  • Tone surfaceTone was changed from 10 to 5.
  • Tone backgroundTone was changed from 10 to 5.

Sep 2, 2022

DOCS

• Readme: Removed old notice about package being a beta release and using Flutter 3.3 beta.
• Readme: Described custom FlexTones config with an example.
• API doc improvements.

EXAMPLE

• Allow selection of example custom tones example and all built-in FlexTones options.
• Publish example app as a live web demo.

Aug 30, 2022

First stable release.

• Document updates.
• Updated minimum dependencies to Dart >=2.18.0 and Flutter >= 3.3.0.

Aug 28, 2022

NEW

• From Material Color utilities export and show Cam16.

Aug 27, 2022

NEW

• Add customization possibility of error tonal palette to the default FlexTonalPalette constructor.

BREAKING

• The FlexTonalPalette method asList and constructor fromList, now include the values of the error color in produced asList, and as required values in fromList.

Aug 27, 2022

• Fix pub points.

Aug 27, 2022

• Relax version constraint to make it work on beta 3.3.0-0.3.pre and later.
• Remove in Flutter beta 3.3.0 unsupported ColorScheme colors scrim and outlineVariant.

Aug 26, 2022

• First dev release of the package.