Bug 515122

Summary: KWin Wayland 6.5.x sometimes initializes wrong color/sharpness on external monitor; fixed by kwin_wayland --replace
Product: [Plasma] kwin Reporter: rxr <rajaroy495>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: REPORTED ---    
Severity: normal CC: kde, rajaroy495
Priority: NOR    
Version First Reported In: 6.5.5   
Target Milestone: ---   
Platform: EndeavourOS   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description rxr 2026-01-26 17:37:53 UTC
On Plasma 6.5.5 (Wayland), external monitors connected via DisplayPort sometimes initialize with incorrect color/sharpness after login.

Symptoms:
- Colors appear over-saturated / HDR-like
- Text looks extremely sharp or over-processed
- Gamma, brightness, and color settings have no effect
- Issue occurs non-deterministically (sometimes fixed after reboot)

Running:
  kwin_wayland --replace &

immediately fixes the issue without logging out, suggesting a KWin Wayland initialization bug in the color/scaling pipeline.

Environment:
- Plasma: 6.x
- KWin: 6.5.5
- Session: Wayland
- External monitor via DisplayPort
- Distribution: EndeavourOS (Arch-based)

The issue does not occur when using Plasma (X11).