That’s even scarier, if it only happened once. 🙂 It shouldn’t have anything to do with the GPU, I suspect you somehow managed to trick the color picker to think that it’s on a different position compared to where it actually was, and as a result it picked the wrong color. I’ve tried everything I thought that could be related on your resolution, but no luck. Let me know if it happens again, and take a screenshot, it helps a lot.