My BMs wore different, black knee-length dresses. The guys were in black suits. To add some color, the BM bouquets were all red and I purchased burgundy pashminas for all of them. I also gave them a burgundy orchid to wear in their hair. They
were really happy that they got to choose their own dresses, especially since they are all very different body types. And they could seriously wear their dresses again.
I was really surprised that I got absolutely no flack for them wearing black... even from my MIL. I guess I lucked out.
Once you make a decision, stand by it and don't let others try to guilt you into changing your mind. It won't look like a funeral, it will look classy and elegant. And your girls will thank you. ;-)
Good luck!