Blondes may have more fun, but according to Nicole Richie, brunettes have more I.Q. points. At least that's what she joked on Twitter this weekend.

Nicole debuted her new darker locks at Costa Mesa's Bloomingdale's, where she was promoting her House of Harlow 1960 holiday jewelry collection.

"OH! & P.S. I went brunette. I feel smarter already," she Twittered.

That she did. It seems like just yesterday she was wandering around like a mess. But now she looks great, in our opinion - regardless of hair color!

Which color do you think suits her locks best, though? Vote below!

Nicole Richie totally looks better as a ...