Buy high quality bulbs. Look in your manual and it'll say which bulbs you need. If you go to Kragen, Pep boys etc... and buy a pair of their blue dome light bulbs, they'll turn greenish yellow in about 30 seconds of the dome being on. So, either buy ones that are guaranteed not to change color, or don't buy them at all.
i tried the Kragen blue type, it turned green in the parking lot of the store. I popped them out and returned them right htere.