(In reply to comment #7)
> Actually, my assumption from Rafał's description was that he's only seeing
> the problem on one of several connected displays at a time, which would
> indicate a problem in the display pipeline instead (assuming all displays
> are showing the same contents or are all updating their contents while the
> problem occurs). Rafał, is my assumption correct?

That's right. I got wrong colors on HDMI-0 while everything was fine on eDP at
the same time.