well, i just became a kde plasma maxi
all of my displays are now pretty close to the same contrast, brightness and color balance
this was impossible with gnome, not to mention a host of other bullshits to deal with
i can't quite see how it has a per-screen adjustment but it's close enough now that if i had a hardware color calibrator i could have some sort of semblance of uniform color... the little display is a little washed out compared to the big ones but it's near enough i'm gonna call it