Bug 515266

Summary:	New plasma releases break secondary display color for some apps
Product:	[Plasma] kwin	Reporter:	Thomas Makin <halorocker89>
Component:	colour-management	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	major	CC:	xaver.hugl
Priority:	NOR
Version First Reported In:	6.5.5
Target Milestone:	---
Platform:	Neon
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Thomas Makin 2026-01-29 15:42:23 UTC

After updating to Plasma 6.5.5 (tested on KDE Neon 24.04 and Fedora 43), an issue crops up where if I launch a chrome-based browser (maybe other XWayland apps too?) on my laptop screen and then drag them to a secondary monitor, they appear in what looks like 256 colors mode. Relaunching on ext screen fixes the issue. None of the displays support HDR.

99% sure this is KDE bug and not Chrome given it has been happening since the update. Definitely happened in last 2 weeks. Replicated on AMD and Intel platforms.

STEPS TO REPRODUCE
1.  Connect laptop to external display
2.  Launch a Chromium browser on internal display
3.  Drag to secondary screen

OBSERVED RESULT
Dragging some apps to ext screen drops color mode

EXPECTED RESULT
No change in color mode

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:  KDE Neon 24.04, Fedora 43
KDE Plasma Version: 6.5.5 (from neon system)
KDE Frameworks Version: 6.22.0 (from neon system)
Qt Version: 6.10.1 (from neon system)

Comment 1 Thomas Makin 2026-01-29 17:51:34 UTC

Aha! Appears to be an EDR issue-- disabling EDR on internal panel stops it from happening.

Comment 2 Zamundaaa 2026-01-29 22:45:25 UTC


*** This bug has been marked as a duplicate of bug 514868 ***