Scala/Art Resource, NY

The son of man, seated on his throne of glory and surrounded by angels, “will put the sheep at his right hand and the goats at the left. Then the king will say to those at his right hand, ‘Come, you that are blessed by my Father, inherit the kingdom prepared for you’…Then he will say to those at his left hand, ‘You that are accursed, depart from me in to the eternal fire prepared for the Devil and his angels’” (Matthew 25:33–34, 41). In this sixth-century mosaic from the Church of Saint Apollinare Nuovo, in Ravenna, Italy, the condemned are accompanied by a blue angel, whose supernatural coloring may identify this figure as Lucifer. The fallen angel is often represented as blue or green.