I am wearing casablanca 1985 in champagne (although it looks like an ivory to everyone who has seen it.) Bridesmaids are in black full length gowns. Tuxedos will be black, do I need to insist on a ivory shirt for the tuxes? I really like the look of the white shirt - especially on the groom who will be wearing a graphite vest/bow tie, but the tux people are saying this will make my dress look darker and drab when I stand next to him.