That was interesting, thanks for sharing!
My favourite colour themes are usually accompanied by black. I like to mix red + black, purple + black and black and white. I also like a bit of neon green and neon or azure blue. But I like colours like dark green and brown occasionally too. I usually dress my avatar with some kind of horns and a tail, since my username refers to a demon. So it's my recurring avatar theme I guess.
I think my colour choices reflect quite well what I like IRL too. I try to avoid yellow and pastel pink. To me the worst combination ever is pastel blue, yellow and red together.
Like this is a cool painting but the colours make me want to shout "how awful":
http://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Isak_Wacklin_Miss_Heckford.jpg/220px-Isak_Wacklin_Miss_Heckford.jpg