I thought the orchid gown by designer Rodarte that Natalie Portman wore at the Oscar's was a gorgeous color! As was the similar color that Alicia Keyes wore by Armani Prive.
I immediately thought what a beautiful color option for your bridesmaids, as it looks good on every skin tone, and not to mention goes fabulously with so many flowers. Here are a few purple variations, top left Amsale, left Lazaro, lower left J. Crew and below with the flower accent Lazaro