The Krewe of REX began in 1872. This Krewe introduced the colors of purple, green and gold as the official colors of Mardi Gras. The REX organization declared that purple, green and gold signified justice, power and faith respectively.

The King of REX transformed Mardi Gras into an official holiday for the City of New Orleans. This organization has entertained historical figures such as the Duke and Duchess of Windsor. Krewe of REX parades each Fat Tuesday morning after the Krewe of Zulu without fail.