I've dated all hair colors (brown, black, blond, red), so I guess I'm not picky. Although hair color isn't the first thing I notice. There are many factors that go into attraction.
Not everyone can dye their hair a different color and look good either. For instance I would look horrible with blond hair. Some people look worse with darker hair or more pale.
Red hair is pretty hot. My current girlfriend is naturally red but thinking of dying it brown. I don't want her to. It looks great. But typically I always thought my type was brown hair, as I think it flatters a lot of girls. I went through a "blonde phase" but that is probably my least favorite.
It does not work that way. Every girl has her own color that looks good on her. Brunette can look amazing on one girl, and trashy on another one. So, you have to figure out what color suits you best. If most guys like Blond (for example), it does not mean that blond will look great on you.