I had once wrong colors with the Trusty initial stack (3.13), which I couldn't reproduce.
And I was just told that disabling DPMS / monitor power management in KDE also prevents the problem, which might correlate with the fact, that running a DPMS "force off" / "force on" cycle also restores the colors correctly.
Now I tried all the Trusty HWEs and it seems to have started with Wily.
xserver- xorg-video- radeon- lts-wily 1:7.5.0+ git20150819- 0ubuntu1~ trusty1 generic- lts-wily 4.2.0.42.34 xorg-core- lts-wily 2:1.17. 2-1ubuntu9. 1~trusty1 1ubuntu4~ trusty1
linux-image-
xserver-
mesa-lts-wily 11.0.2-
I had once wrong colors with the Trusty initial stack (3.13), which I couldn't reproduce.
And I was just told that disabling DPMS / monitor power management in KDE also prevents the problem, which might correlate with the fact, that running a DPMS "force off" / "force on" cycle also restores the colors correctly.