Is this bike going to have brakes?
I really love black rims and spokes on a brakeless bike, they look mean and sexy. However, if you put them on a bike with brakes they get that shiny stripe on them and I don't dig that. Worst of all is a bike with only a front brake with black rims, then you get only one wheel with a stripe. Ewwwwwww.
All this assumes that you get rims that are totally black by the way, and not ones with a shiny machined stripe on them in the first place.
I usually don't like to demonstrate how much of a style nerd I am.... but you asked.