These are the callsites of BuilderState::colorFromPrimitiveValueWithResolvedCurrentColor. See the comments there.
Some of these don't work for other reasons too, for example we don't support 'inherit' for content property.
https://wpt.fyi/results/css?label=master&label=experimental&aligned&view=subtest&q=currentcolor%20safari%3Afail
<rdar://problem/108685171>