Bug 512157

Summary: chrome canary with HDR and KDE's night light has red tinted zones
Product: [Plasma] kwin Reporter: ctj9512
Component: colour-managementAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: xaver.hugl
Priority: NOR    
Version First Reported In: 6.5.0   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description ctj9512 2025-11-15 20:54:19 UTC 
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SUMMARY

chrome canary with HDR and KDE's night light has red tinted zones

STEPS TO REPRODUCE
1. Use Google Chrome Canary (reproducible on version 144.0.7526.3)
2. Enable KDE Night Light
3. Open chrome:help

OBSERVED RESULT
1. The white background has zones that are more tinted (night light color shift) than others

https://issues.chromium.org/446254087#attachment70835140

EXPECTED RESULT
1. The white background should look as a solid color

SOFTWARE/OS VERSIONS

Operating System: Arch Linux
KDE Plasma Version: 6.5.0
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.12.55-1-lts (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7735HS with Radeon Graphics
Memory: 96 GiB of RAM (93.5 GiB usable)
Graphics Processor 1: AMD Radeon RX 7700S
Graphics Processor 2: AMD Radeon 680M

ADDITIONAL INFORMATION

A similar issue was reported on https://issues.chromium.org/issues/446254087, however I believe this is more likely to be a kwin bug, since the compositor is responsible for night light colors, and is applied after any application's output is rendered.
Comment 1 Zamundaaa 2025-11-17 15:47:25 UTC 
(In reply to ctj9512 from comment #0)
> A similar issue was reported on
> https://issues.chromium.org/issues/446254087, however I believe this is more
> likely to be a kwin bug, since the compositor is responsible for night light
> colors, and is applied after any application's output is rendered.
Our night light implementation is a bit more complicated than that. The short summary is that KWin
1. adjusts the white point on the output and
2. applies an additional transformation from that changed white point to the actual screen

Step 2 always happens in the compositor, and specifically on the fully composited image for the display, so nothing app-specific.
Step 1 however can be applied in either the compositor or in the app. If the app has a different white point, KWin transforms from that to the screen, but if it matches, it doesn't do anything.

In Chrome's case, it adjusts colors to the changed white point itself, so KWin doesn't do anything with Chrome's window. Please report this to Google.
Comment 2 ctj9512 2025-11-20 08:52:25 UTC 
Chromium bug report: https://issues.chromium.org/issues/461845657