With light brown, you have so mnay options. You could go with teal, or burgundy, a deep rose, dark green. Or if you want a really sophisticated look, stay with neutrals--shades of brown, copper, metallic gold, black. My dd has her entire apt, in neutrals, and while it's not something I'd ever choose (I LOVE color), it's striking.

I'd try to have a good contrast in value (intensity), but pretty much any color could go nicely with a light brown. What else are you working with? what color are the fixtures? the vanity? the floors/ceilings/walls?