Masks are frequently worn or painted on faces in Chinese operas and other theater productions. The facial makeup dates back to the Song (960 to1279 A.D.) or Yuan (1271 to1368 A.D.) Dynasties, or earlier. Murals in tombs from this period of time have similar-looking made-up faces. The face painting was perfected during the Ming Dynasty (1368 to1644 A.D.), when colors began to portray varying personality traits that are still seen in present day "Jingju," or Beijing operas. Red stands for being devoted, brave, upright and loyal. Guan Yu, general of the Three Kingdoms in 220 to 280 A.D., is depicted with a red face because of his steadfastness on behalf of Emperor Liu Bei. Black paint depicts a fierce and bold character. This color is exemplified by Bao Gong, also called Bao Zheng, who was a fearless though fair judge during the Song Dynasty.