Created attachment 176651 [details] Screenshots I've temporarily connected my screen (supports 10 bit/c) with an HDMI cable and I've found that gray colors are not distinguishable from white, unless the brightness slider in the Brightness and Color applet is put to 80%. The issue does not appear, when the screen is connected with an DP cable. There's no ICC profile applied. Please see phone capture comparison attached. SOFTWARE/OS VERSIONS Operating System: openSUSE Tumbleweed 20241211 KDE Plasma Version: 6.2.4 KDE Frameworks Version: 6.8.0 Qt Version: 6.8.1 Kernel Version: 6.11.8-1-default (64-bit) Graphics Platform: Wayland Graphics Processor: AMD Radeon RX 580 Series inxi -G ``` Graphics: Device-1: Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] driver: amdgpu v: kernel Display: wayland server: X.org v: 1.21.1.14 with: Xwayland v: 24.1.4 compositor: kwin_wayland driver: X: loaded: amdgpu unloaded: modesetting,vesa dri: radeonsi gpu: amdgpu resolution: 1920x1080 API: EGL v: 1.5 drivers: kms_swrast,radeonsi,swrast platforms: gbm,wayland,x11,surfaceless,device API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 24.3.1 renderer: AMD Radeon RX 580 Series (radeonsi polaris10 LLVM 19.1.5 DRM 3.59 6.11.8-1-default) ```
That sounds a lot like the screen is expecting limited range, but is sent full range content instead - so the top few % brightness steps just get cut off. Unfortunately amdgpu doesn't allow you to override its choice for limited/full range yet, see https://gitlab.freedesktop.org/drm/amd/-/issues/476 for more information about that