Update: Turning off Advanced Lighting, as someone suggested in another thread, resulted in being able to see animated characters such as in the sovereign or unit creation screens, however the round static portraits in the main game screen were still whited out.
I then disabled "Transform and..." and that fixed the round static portraits. This also seemed to make the game much more stable as I was able to play for 50+ turns before CTD, whereas before I rarely got to turn 10.
I also tried starting a new game from within a running game and many of the issues came back. Animated portraits I could see but there was some kind of white overlay and artifacts (screenshot), and the main game was again all white.