NEW305672
On some displays, CSS colors when used as layer backgrounds can still show as HDR 
https://bugs.webkit.org/show_bug.cgi?id=305672
Summary On some displays, CSS colors when used as layer backgrounds can still show as...
Simon Fraser (smfr)
Reported 2026-01-16 15:52:30 PST
Created attachment 478057 [details] Test On a Studio Display, the left boxes in the attached testcase still show as HDR, even though we intend to clamp. `colorSpace.usesExtendedRange()` returns false for the Apple Studio Display, even though it has some HDR headroom. This causes `cachedSDRCGColorForColorspace()` and `createSDRCGColorForColorspace()` to not clamp as they should.
Attachments
Test (2.47 KB, text/html)
2026-01-16 15:52 PST, Simon Fraser (smfr) 		no flags
Details
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Radar WebKit Bug Importer
Comment 1 2026-01-16 15:52:35 PST
<rdar://problem/168331427>
Simon Fraser (smfr)
Comment 2 2026-01-16 15:53:38 PST
There has to be another HDR asset on the screen for that test case to show HDR.
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