How do I fix the Nightingale Hood glitch where it turns white instead of its normal black color?
OK, so it seems like this is a problem with the shaders after a patch some time ago. After browsing several forums, it seems like the only solution (someone says it's permanent and someone says it's temporary) is to put the hood on a mannequin in a house, leave the house and restart you game. When you go back in it should be fixed!
Sources: gamefaqs theskyrimblog