It may very well not matter at all. Wear whatever makes you look fantastic (but not on a level that competes with the bride).

Do you know what the bridesmaids' colors are? I once went to a wedding were the bridesmaids wore black dresses with a small white sash around the waist. Most of the guests wore black and khaki. And there was a bagpipe player outside. I swear, other than the white limo, people would've thought it was a funeral going on.