Hmm...I had the same problem with my 530d, first I was 100% sure I wanted Imperial Blue with oyster/oyster interior. Then I saw a carbon black F11 and it looked stunning! However, Carbon black is hopeless to maintain from what I have heard. Every little scratch will be visible. After this I finally went for Sophisto Grey II...it is a very nice color as it almost looks black when it is dark outside and dark grey in sunlight. In combination with 351M 19" wheels and oyster/black interior the car is a beaut!
Good luck with your choice!