Bug 495647

Summary:	GTK4 apps are super bright
Product:	[Plasma] kwin	Reporter:	Oleg <dreamkepeer>
Component:	colour-management	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	eifr0980, nate, xaver.hugl
Priority:	NOR
Version First Reported In:	6.2.2
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	HDR video (watch in mpv) kooha log with WAYLAND_DEBUG

Description Oleg 2024-10-31 16:35:33 UTC

SUMMARY
Some GTK4 apps (like Kooha) are super bright in KDE, and it seems like they're using HDR brightness for some reason even though they're not running with VK HDR layer.

STEPS TO REPRODUCE
1.  Open Kooha

OBSERVED RESULT
Interface will be super bright. No such problem on X11.

EXPECTED RESULT
Should be just like on X11.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.2.2
KDE Frameworks Version: 6.7.0
Qt Version: 6.8.0
Kernel Version: 6.11.5-3-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-7700K CPU @ 4.20GHz
Memory: 15.6 ГиБ of RAM
Graphics Processor: AMD Radeon RX 6700 XT

ADDITIONAL INFORMATION
Some people reported similar issues with other GTK4 apps: https://www.reddit.com/r/kde/comments/1gg9kd8/has_anyone_noticed_gtk4_apps_look_kinda_saturated/

Comment 1 Nate Graham 2024-11-01 15:45:05 UTC

Can you attach a screenshot of how it looks got you? It looks okay to me.

Comment 2 Oleg 2024-11-01 18:19:47 UTC

Created attachment 175457 [details]
HDR video (watch in mpv)

I can't post a screenshot where it is clearly seen, but here's video with HDR metadata recorded (although colors are a bit wrong).

Comment 3 Nate Graham 2024-11-04 17:41:14 UTC

Thanks!

Comment 4 Zamundaaa 2024-11-04 21:38:56 UTC

Please attach the output of
> WAYLAND_DEBUG=1 kooha

Comment 5 Oleg 2024-11-05 15:08:40 UTC

Created attachment 175552 [details]
kooha log with WAYLAND_DEBUG

Here it is

Comment 6 Oleg 2024-11-17 19:48:52 UTC

Updating the status

Comment 7 Zamundaaa 2024-11-18 16:52:04 UTC

Okay, GTK is using the BT2020+PQ here, so it's definitely a bug in GTK. FWIW I talked with GTK maintainers about this, and they now disabled using the color management protocol by default again in GTK because their implementation wasn't good enough yet... So this should go away with a future GTK update.
You can work around it with the environment variable GDK_DISABLE=color-mgmt for now

Comment 8 Vlad Zahorodnii 2025-02-05 13:53:00 UTC

*** Bug 499507 has been marked as a duplicate of this bug. ***