When I turned on the Adv. Lighting button in the Video tab of the options menu all of the character models in portraits were all white, as if lighting went crazy and decided to shade everything white. Sometimes the lining of the character's clothes, as in the colour, would appear but that's it.
This affected the Soverign creation screen, character portraits and the entire game map zoomed in, not in cloth mode. No matter how low I turned the slider down I still had the problem. It was only until I unchecked the box that the problem was solved.
My specs are:
Intel Centrino duel core 2.00 GHz
Nvidia 7950GTX GO GPU with the latest driver support
4 gigs of RAM
XP Professional OS