LGTM3 On Wed, Mar 4, 2026, 6:43 AM Vladimir Levin <[email protected]> wrote:
> LGTM2 > > On Wed, Mar 4, 2026 at 9:26 AM Mike Taylor <[email protected]> wrote: > >> LGTM1 - thanks for catching us up here. >> On 3/4/26 8:51 a.m., Rune Lillesveen wrote: >> >> *Contact emails* >> [email protected] >> >> *Specification* >> https://drafts.csswg.org/css-color-5/#contrast-color >> >> *Summary* >> This function is used to meet contrast requirements for accessibility. >> The contrast-color() function can be used anywhere in CSS where a color >> value is expected. It takes a color value argument, and returns either >> 'black' or 'white' depending on which of them gives the highest contrast >> against the color argument. >> >> The contrast algorithm is UA-defined per spec. >> >> Blink's implementation uses an existing WCAG-based implementation: >> >> >> https://source.chromium.org/chromium/chromium/src/+/37ec5d082cb1df8959857653854677200fdb334c:ui/gfx/color_utils.h;l=43-51;bpv=0 >> >> This is the same as the Firefox implementation[1] and Safari which have a >> detailed description about the WCAG algorithm and its shortcomings in their >> blog post[2]. >> >> [1] >> https://github.com/mozilla-firefox/firefox/blob/main/servo/components/style/values/computed/color.rs#L104-L128 >> [2] https://webkit.org/blog/16929/contrast-color/ >> >> *Blink component* >> Blink>CSS >> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3ECSS%22> >> >> *Web Feature ID* >> contrast-color <https://webstatus.dev/features/contrast-color> >> >> *Motivation* >> This feature will make it easier for authors to meet contrast >> requirements for accessibility. The feature is already shipped in the two >> other major engines. contrast-color() is also part of Interop 2026. >> >> *Initial public proposal* >> *No information provided* >> >> *TAG review* >> *No information provided* >> >> *TAG review status* >> Not applicable >> >> *Risks* >> >> >> *Interoperability and Compatibility* >> *No information provided* >> >> *Gecko*: Shipped/Shipping ( >> https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values/color_value/contrast-color#browser_compatibility >> ) >> >> *WebKit*: Shipped/Shipping ( >> https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values/color_value/contrast-color#browser_compatibility >> ) >> >> *Web developers*: No signals >> >> *Other signals*: >> >> *WebView application risks* >> >> Does this intent deprecate or change behavior of existing APIs, such that >> it has potentially high risk for Android WebView-based applications? >> *No information provided* >> >> >> *Debuggability* >> *No information provided* >> >> *Will this feature be supported on all six Blink platforms (Windows, Mac, >> Linux, ChromeOS, Android, and Android WebView)?* >> Yes >> >> *Is this feature fully tested by web-platform-tests >> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* >> Yes, but given that the contrast algorithm is UA-defined per spec, most >> expectations allow both white and black as the returned contrast-color(). >> >> >> https://wpt.fyi/results/css/css-color/animation/contrast-color-interpolation.html >> https://wpt.fyi/results/css/css-color/contrast-color-001.html >> >> https://wpt.fyi/results/css/css-color/contrast-color-currentcolor-inherited.html >> >> https://wpt.fyi/results/css/css-color/parsing/color-computed-contrast-color-function.html >> >> https://wpt.fyi/results/css/css-color/parsing/color-invalid-contrast-color-function.html >> >> https://wpt.fyi/results/css/css-color/parsing/color-valid-contrast-color-function.html >> >> https://wpt.fyi/results/css/css-color/parsing/contrast-color-function-calc-container.html >> >> https://wpt.fyi/results/css/css-images/color-stop-contrast-color-currentcolor-invalidation.html >> >> *Flag name on about://flags* >> *No information provided* >> >> *Finch feature name* >> *No information provided* >> >> *Non-finch justification* >> *No information provided* >> >> *Rollout plan* >> Will ship enabled for all users >> >> *Requires code in //chrome?* >> False >> >> *Tracking bug* >> https://crbug.com/40142548 >> >> *Estimated milestones* >> Shipping on desktop 147 >> Shipping on Android 147 >> Shipping on WebView 147 >> >> *Anticipated spec changes* >> >> Open questions about a feature may be a source of future web compat or >> interop issues. Please list open issues (e.g. links to known github issues >> in the project for the feature specification) whose resolution may >> introduce web compat/interop risk (e.g., changing to naming or structure of >> the API in a non-backward-compatible way). >> *No information provided* >> >> *Link to entry on the Chrome Platform Status* >> https://chromestatus.com/feature/4841046007742464?gate=6582039723769856 >> >> *Links to previous Intent discussions* >> Intent to Prototype: >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACuPfeTv1YNDgDkc5SiCDwDf0ZCn0sWd7qdfUzuQvejpEut8tA%40mail.gmail.com >> >> >> This intent message was generated by Chrome Platform Status >> <https://chromestatus.com/>. >> >> -- >> Rune Lillesveen >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACuPfeTdz0K67%2BRocOJHjABqXBLiMcUwFUMrhLrhvhGGfWGKeg%40mail.gmail.com >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACuPfeTdz0K67%2BRocOJHjABqXBLiMcUwFUMrhLrhvhGGfWGKeg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/cea2459b-90f7-45e0-bef0-efa04555a948%40chromium.org >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/cea2459b-90f7-45e0-bef0-efa04555a948%40chromium.org?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADsXd2PMTahvCZczFkzwL1MoPbt25dv6QARuPgW%3D4yChmnzTzA%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADsXd2PMTahvCZczFkzwL1MoPbt25dv6QARuPgW%3D4yChmnzTzA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw8nnE%3DgxKNEzGK8TjV5pzt_NYAdQiArWSnHTmBCbDF72Q%40mail.gmail.com.
