When I was selling bikes, I decided that color is more of a veto issue, at least for men. I can't tell you how many times guys have said to me something like: "I don't care about color. I'll take the next one that comes off of the assembly line." The very next words out of their mouth might be: "Not green."
I might take some sexist heat for saying this, but my experience has been that women are a bit more selective. I've actually had at least one woman come into the store and say: "I want to buy a blue bike."
Personally, I won't ride a bike that I think looks ugly.