I read somewhere about a wedding (or weddings) where the bride gave the bridesmaids a color, and let them pick out their own style. Or maybe it was that the bride gave them a style and let them pick their own color. Either way is good.
I had purchased and worn enough hideous bridesmaid dresses, that by the time I got married, I chose not to have a full-on "wedding party." Too much work.
We had a maid of honor, a best man and a flower girl. That's it. I asked the maid of honor to go find a dress she liked -- gave her a few color ideas. Turned out she already had a dress that worked perfectly. The flower girl, I bought her dress for her (it was simple and white) but let her mom help pick it out. The best man, we asked him to just wear a dark suit.
Everyone was much happier for it. No drama, no unnecessary expense.