Sounds like corrupted graphics render. On my version of the game, none of these dungeons cause such issues. Did you try to reinstall the game / run it with lower graphics? Wolf den specifically seems to have weather effects (Grim, cloudy weather) and maybe if that is not rendering properly, it appears as a purple/black mess. Could you name which dungeons specifically give you this trouble? That might shed more light on the issue. (BEFORE reinstalling, you might wanna backup your save file - the game currently only has one active save, its the file named profile.txt or smthing like that.)
