just been watching We Dive at Dawn. The bride wears a dress that someone says is green (the film was black and white) and people suck in their teeth. The groom is suddenly recalled to his ship, to his great relief, but it's bad luck for the bride.
Even if it's ominous for the bride, though. this doesn't apply to guests.
There was a girl in my hairdresser's yesterday on her way to her brother's wedding and she looked stunning in a green dress and matching headpiece. If you suit it wear it!