Just curious, anyone on newer versions of Windows 11, can they change gamma in games like DOOM 3, Quake 3 / 4, Call of Duty 1 / UO, Return to Castle Wolfenstein etc. I mean the original versions, not source ports that exist for some of these. I remember these games changing gamma in a way that persisted in case if game was abruptly closed or if you tried to switch away to another program, wasn't limited to game window.

Well it doesn't work on my Win11 23H2. Console always reports gamma as "software" regardless of r_ignorehwgamma setting and moving gamma slider doesn't actually change it. DOOM 3 specifically reports that SetGammaRamp failed, though I'm going off by EXE I self-compiled while changing some smaller things years ago related to alt-tabbing, I might have broken something along the way.