SUMMARY Windows dimmed via either the Dialog Parent or Dim Inactive effects appear noticeably brighter when lowering the screen brightness below 100% with a monitor/connection that doesn't expose hardware brightness control to the system. STEPS TO REPRODUCE 1. Set screen brightness to 100% 2. Enable Dim Inactive effect and open multiple windows 3. Lower screen brightness by 1% (or more) OBSERVED RESULT The inactive windows dimmed by the effect get a little less dimmer despite everything else getting +1% more dim. They continue to get dimmer as expected from this point downwards, but with their baseline brightness is slightly higher. EXPECTED RESULT Windows don't go slightly brighter below 99% as opposed to full brightness and scale brightness uniformly with the rest of the screen. SOFTWARE/OS VERSIONS Linux: Arch KDE Plasma Version: 6.4.4 KDE Frameworks Version: 6.17.0 Qt Version: 6.9.1
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/8244
Git commit 37ae2f1bd1182667b84752b393992c4be6b27002 by Xaver Hugl. Committed on 17/10/2025 at 11:13. Pushed by zamundaaa into branch 'master'. scene/itemrenderer_opengl: always apply modulation and saturation in linear Otherwise it can look different just depending on whether or not other color management steps happen to be applied M +7 -2 src/scene/itemrenderer_opengl.cpp https://invent.kde.org/plasma/kwin/-/commit/37ae2f1bd1182667b84752b393992c4be6b27002
Git commit aa1ed206446b904beb93d2ca5bd8aa77bbf1abed by Xaver Hugl. Committed on 20/10/2025 at 11:17. Pushed by zamundaaa into branch 'Plasma/6.5'. scene/itemrenderer_opengl: always apply modulation and saturation in linear Otherwise it can look different just depending on whether or not other color management steps happen to be applied (cherry picked from commit 37ae2f1bd1182667b84752b393992c4be6b27002) M +7 -2 src/scene/itemrenderer_opengl.cpp https://invent.kde.org/plasma/kwin/-/commit/aa1ed206446b904beb93d2ca5bd8aa77bbf1abed