I had the exact same thing happen as I adjusted my gamma slightly darker to make a cv stand out. I was about 2 minutes out when I did this. I remembered that escaping to desktop and returning always changes my gamma I hit the Windows key, then clicked on AHII in the task bar to go back. It still looked weired but I could read my e6b, instruments, and see the cv (but not much else in the way of details). A reboot fixed everythign.