It seems that 258448@main mistakenly turned on the color part of CSS Typed OM which is incomplete and definitely not ready to ship.
<rdar://problem/108158754>
Pull request: https://github.com/WebKit/WebKit/pull/12821
Committed 263039@main (4a4fce197e49): <https://commits.webkit.org/263039@main> Reviewed commits have been landed. Closing PR #12821 and removing active labels.