Created attachment 184150 [details] phone photos of the screen hopefully showing the colors before and after reproducing the bug SUMMARY With HDR enabled colors look wrong in that they heavily saturate and crush. I first noticed this on my Arch linux system where I routinely run kscreen-doctor --dpms off and occasionally I would wake the display up and see saturated and crushed colors. However, switching to TTY and back looks like the same issue and is easier to reproduce. I've also been able to reproduce on Neon. STEPS TO REPRODUCE 1. Boot Neon Testing edition live cd 2. Enable HDR in display settings 3. Switch to a tty and back OBSERVED RESULT Colors crush and saturate EXPECTED RESULT Colors stay the same SOFTWARE/OS VERSIONS KDE Plasma Version: 6.4.80 KDE Frameworks Version: 6.18.0 Qt Version: 6.9.1 ADDITIONAL INFORMATION I am also able to reproduce on my archlinux system KDE Plasma Version: 6.4.4 KDE Frameworks Version: 6.17.0 Qt Version: 6.9.1 But was not able to reproduce on Neon User edition KDE Plasma Version: 6.4.3 KDE Frameworks Version: 6.16.0 Qt Version: 6.9.1 Screenshots taken while the bug is active look fine. To put colors back to normal just toggle HDR off and on. kscreen-doctor -o Output: 1 DP-1 81a767ee-6d32-4beb-9768-8e23cb774ec2 enabled connected priority 1 DisplayPort replication source:0 Modes: 1:2560x1440@144*! 2:2560x1440@120 3:2560x1440@100 4:2560x1440@60 5:1920x1200@144 6:1920x1080@75 7:1920x1080@60 8:1920x1080@60 9:1920x1080@60 10:1920x1080@50 11:1600x1200@144 12:1680x1050@60 13:1600x900@60 14:1280x1024@75 15:1280x1024@60 16:1440x900@144 17:1280x800@60 18:1152x864@60 19:1280x720@60 20:1280x720@60 21:1280x720@60 22:1280x720@50 23:1024x768@75 24:1024x768@60 25:800x600@75 26:800x600@60 27:720x480@60 28:720x480@60 29:640x480@75 30:640x480@60 31:640x480@60 32:640x480@60 33:1600x1200@60 34:1280x1024@144 35:1024x768@144 36:1920x1200@60 37:1280x800@144 38:1920x1080@144 39:1600x900@144 40:1368x768@60 41:1368x768@144 42:1280x720@144 Geometry: 0,0 2560x1440 Scale: 1 Rotation: 1 Overscan: 0 Vrr: Automatic RgbRange: Automatic HDR: enabled SDR brightness: 343 nits SDR gamut wideness: 30% Peak brightness: 400 nits, overridden with: 400 nits Max average brightness: 344 nits Min brightness: 0.0984 nits Wide Color Gamut: enabled ICC profile: none Color profile source: sRGB Color power preference: prefer efficiency and performance Brightness control: supported, set to 100% and dimming to 100% DDC/CI: allowed Color resolution: automatic (10), range: [8; 16] bits per color Allow EDR: unsupported
This is a driver bug, see https://gitlab.freedesktop.org/drm/amd/-/issues/4444
Git commit d2df32c9c664023bb6a1409dbaecbd3078dbaaec by Xaver Hugl. Committed on 20/08/2025 at 19:38. Pushed by zamundaaa into branch 'master'. backends/drm: work around amdgpu applying GAMMA_LUT in test-only commits See https://gitlab.freedesktop.org/drm/amd/-/issues/4444 for details. This does not cover up all the cases where the bug causes visible issues, but it helps with the most annoying ones (at the cost of some performance during brightness or color temperature animations). For testing potential driver fixes, KWIN_DRM_DISABLE_AMD_GAMMA_WORKAROUND can be set to 1 to disable this workaround. M +5 -1 src/backends/drm/drm_colorop.cpp https://invent.kde.org/plasma/kwin/-/commit/d2df32c9c664023bb6a1409dbaecbd3078dbaaec
Git commit 7d36003cb073ed2ad48b2743883db993106c347a by Xaver Hugl. Committed on 20/08/2025 at 21:12. Pushed by zamundaaa into branch 'Plasma/6.4'. backends/drm: work around amdgpu applying GAMMA_LUT in test-only commits See https://gitlab.freedesktop.org/drm/amd/-/issues/4444 for details. This does not cover up all the cases where the bug causes visible issues, but it helps with the most annoying ones (at the cost of some performance during brightness or color temperature animations). For testing potential driver fixes, KWIN_DRM_DISABLE_AMD_GAMMA_WORKAROUND can be set to 1 to disable this workaround. (cherry picked from commit d2df32c9c664023bb6a1409dbaecbd3078dbaaec) Co-authored-by: Xaver Hugl <xaver.hugl@kde.org> M +5 -1 src/backends/drm/drm_colorop.cpp https://invent.kde.org/plasma/kwin/-/commit/7d36003cb073ed2ad48b2743883db993106c347a