Since no one else suggested the obvious, have you checked the VGA/HDMI/DVI cable? Contrasts can be caused by a number of things, the simplest being a change in frequency/refresh rates/resolution and the signal travelling through the cable. If the contacts are arcing (on an incredibly tiny scale) it could very well only become present in the game when it launches at a different resolution then the host OS.
TL;DR:
Wiggle, flex, and swap the video cable while you have contrast on screen, (if possible) to eliminate it as a possible culprit. You want a good, snug, screwed down (if applicable) connection with no internal breaks in the copper strands. Easiest starting point. Then we can move to other hardware/software as being the cause.
IT isn't about knowing what IS wrong, but rather, eliminating what ISN'T the problem.