Morning dress, also known as formal day dress, is the formal Western dress code for day attire, consisting chiefly of, for men, a morning coat, waistcoat, and formal trousers, and an appropriate gown for women. Men may also wear a popular variant where all parts are the same colour and material, often grey and usually called "morning suit" or "morning grey" to distinguish it; considered properly appropriate only to festive functions such as summer weddings and horse races, which consequently makes it slightly less formal. The correct hat would be a formal top hat, or if on less spacious audience settings optionally a collapsible equivalent opera hat.