“The gods of the underworld, such as the Greco-Roman Plouton or Pluto, are lords of both fertility and death. The Devil’s association with hell comes from his identification with the malevolent aspects of the subterranean lord. The red glow of hellfire, together with the red tint of land scorched by fire and with the color of blood, led to the association of the Devil with the color red.”

—Jeffrey Burton Russell, from The Prince of Darkness: Radical Evil and the Power of Good in History, 1988.