What color flowers would match?

I am attending a winter formal in a few weeks and I am having trouble deciding how to coordinate things. My dress is solid olive-y green (long, shiny silk). My shoes and purse are white and his tux jacket, pants, vest, and shirt are black with a white tie. So, my dilemma is whether to get white, light pink, or yellow roses in my corsage and his boutoniere. Or maybe another color? And what color ribbon to have them tied with (white, black, or olive?). Thanks!