Place ½ cup sugar in each of three small resealable plastic bags.
In a small bowl, combine red and blue food coloring until it turns purple. Add purple food coloring to one bag, green coloring to another bag, and yellow coloring to third bag; seal bags, and shake each until sugar is even in color.
Recipe by Louisiana Cookin' at https://louisianacookin.com/creole-cream-cheese-and-satsuma-king-cake/