I recently upgraded my 27" iMac to El Capitan and every now and then the screen gets ...weird. The best way to describe it is if I went into the "Accessibility" system preference, selected invert colors, and then moved the Display contrast to maximum. Sometimes if I just giggle the mouse the screen returns to normal, but not always (most times if I can get the screen to go into screensaver mode and then exit this mode the screen goes back to normal).
Anyone seen this before, and have any idea what its due to (and how to fix it).
Anyone seen this before, and have any idea what its due to (and how to fix it).