Few rules in life are as stead-fast as “Never wear white to a wedding.” You shouldn't wear any colors that might be mistaken for white either; creme, off-white, or eggshell, especially on a dress, will get you on the wrong side of the couple's family for eternity. Even if you manage to smooth things over with the couple themselves and maintain contact, you'll still be forever known as “that one friend who wore white." Now, if you shouldn't wear white to a wedding, you certainly shouldn't wear a…