Blues and Greens, political factions in the Byzantine Empire in the 6th cent. They took their names from two of the four colors worn by the circus charioteers. Their clashes were intensified by religious differences. The Greens represented Monophysitism and the lower classes; the Blues, orthodoxy and the upper classes. In 532 the two factions joined in the Nika revolt against Emperor Justinian I and Empress Theodora. However, Theodora's resolute stand and the aid of Belisarius and Narses ended the revolt. The factions continued to oppose each other into the 7th cent., but by the 9th cent. they had become mostly ceremonial.