Color Matching

I do website design for a living as well as a hobby, which means sometimes I have to come up with a color that blends well with others. I am really just a computer geek and have no sense of style whatsoever... Sometimes I put Navy with Black... which my sister tells me is an absolute no-no. My creative out-of-the-box thinking side rebels against these sorts of absolute rules, but I guess I should submit to the fact that I am not an expert in this area.
Anyway... I found a color blending tool that just might help me for my web design... Now if I could only find a way to integrate this into my closet, and I will never need a women's help again...