Color theme

You could do bright color flowers and decor to go with the black dress! That will help brighten the overall tone. Maybe something similar to these?

As for colors for your wedding party, you could have everyone wear gold or silver or a light version of any color (lavender, pink, light blue, etc).

Your BMs could absolutely wear white. If you want other color options, you could have them wear white, various greens or a metallic like this mood board:

Or you could do various shades of purple or blue that would look gorgeous with your black dress:

Some shades of olive green or lavender or even a real light blue like the pic listed above would look beautiful to add more color in the wedding 😌