I have no problem with it. I'm 23 and I've been wearing black since the tenth grade. The most color I wear is camo when I'm wearing shorts. Other than that all of my shirts and pants are black. I feel out of place even when I try putting on colors like red or blue etc. So it has nothing to do with being emo, goth or punk etc.
Black just happens to be my favorite color to wear. another plus to having mostly one color is when you go shopping you know what you want and you don't take 2 hours just to pick out a few pairs of clothes.