We fail to pass the WPT test css/css-animations/animate-with-color-mix.html per https://wpt.fyi/results/css/css-animations/animate-with-color-mix.html. As of this writing, only Chromium-based browsers pass.
The test css/css-transitions/animations/animate-with-color-mix.html also fails, likely due to the same reasons.
The issue here is that we're not serializing the color correctly. Scientific notation is not allowed.
Pull request: https://github.com/WebKit/WebKit/pull/26894
Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/45605
Committed 277256@main (a08c3d1966f9): <https://commits.webkit.org/277256@main> Reviewed commits have been landed. Closing PR #26894 and removing active labels.
<rdar://problem/126148201>