Blood Red

When Hernán Cortés invaded Mexico, he found a society besotted with strong sensations, from blood sports to drug-level chocolate, which the Aztecs sometimes stirred with the powdered bones of their enemies. The emperor, Montezuma, claimed the right to wear the most brilliant red and imposed on his subjects a special tax to be paid in cochineal insects, from which the vibrant dye came.

From "To Dye For," a review of A Perfect Red: Empire, Espionage, and the Quest for the Color of Desire (Washington Post via Arts & Letters Daily).