Black & red. I have quite a lot of grey, blue & green items as well.
(and some pink items as well, but I rarely wear those these days)
I don't have a lot of white items though, I guess that's kind of rare. But I have been buying some white items lately, since I like the black-white combos that have been dominating the catwalk during the Fashion Weeks for spring 2007.
And I'm trying to get more purple & violet items at the moment too.