I am getting from time to time completely distorted colors in xorg only after freshly connecting a tft display and the doing xrandr --auto
See photo http://nn7.de/shots/distortion.jpg
Happens on a macbookpro1,1 - yes ddc also does not work but that is probably a different issue.
Ahh and this color awkwardness can be fixed by switching to the vga console and back to X.
*** This bug has been marked as a duplicate of bug 13474 ***