I think I asked this question a little while back in the "Ask a Question" thread...And basically was told that men are from Mars, women are form Venus, and the "rules" of classic clothing for each are just different, with a different history and different traditions.
Example: a criticism of men wearing black suits is that it looks too similar to a tuxedo. Obviously the tuxedo doesn't play a role in a woman's wardrobe, so she's more free to wear a black dress.
However, that doesn't explain how many criticize black suits becuase they make men look washed out, but that criticism is never leveled at women.
I know I prefer midnight blue to black for suiting; maybe women's dresses would look better to me in midnight blue as well.