Let me guess, Gainward?
I recently got mine replaced. It's bad capacitors that cause the colors thing. Gainward warrantees for 3 years, although I had to try about 5 times to get someone present to give me an RMA #. If yours isn't Gainward then find out what the warranty is from your manufacturer.
My wife's did the same thing but sooner so it went to Newegg with less hassle.