SUMMARY Setting "RGB Range" to "Full" still keeps monitor at YCbCr 4:4:4 which looks *bad*. Both Windows and macOS are able to use RGB Full 8-bit on this monitor. I am unsure what logs I should attach here, so please let me know. Just in case I thought it could be a link speed issue, I tried at 60Hz, and it does YCbCr 4:4:4 10-bit color instead for... some reason. I don't find any way to force it on the command line, nor can I use wayland-xrandr to set it (which does work on Window Managers) STEPS TO REPRODUCE 1. Set "RGB Range" to Full 2. Nothing changes, screen doesn't even flash. OBSERVED RESULT [See attachment] EXPECTED RESULT Screen uses RGB Full range. SOFTWARE/OS VERSIONS Linux: 6.15.4 KDE Plasma Version: 6.4.2 KDE Frameworks Version: 6.15.0 Qt Version: 6.9.1 ADDITIONAL INFORMATION
Created attachment 182868 [details] Screen showing YCbCr4:4:4 insteaqd of Full RGB
The RGB range setting does not change the display encoding. It's quite simply not what it's meant to do...
I would argue it's a bit misleading then. Still, how would I set my screen to Full RGB then? KWin is the only compositor where for some reason it's stuck on 4:4:4. El mié, 20 ago 2025 a las 15:25, Zamundaaa (<bugzilla_noreply@kde.org>) escribió: > > https://bugs.kde.org/show_bug.cgi?id=506496 > > Zamundaaa <xaver.hugl@kde.org> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > Status|REPORTED |RESOLVED > Resolution|--- |NOT A BUG > > --- Comment #2 from Zamundaaa <xaver.hugl@kde.org> --- > The RGB range setting does not change the display encoding. It's quite simply > not what it's meant to do... > > -- > You are receiving this mail because: > You reported the bug. > You are on the CC list for the bug.
There's no way to do that, it's unfortunately completely up to the driver. No other compositor can do it either. The only approach I know of is to modify the EDID of the display, to claim that it just doesn't support YCbCr. FWIW, YCbCr 4:4:4 should look exactly identical to RGB 4:4.4, if it doesn't, something else is wrong. You can report that problem to your graphics vendor.