The orange color of some cheddar cheeses traces back to 17th-century England, where beta-carotene-rich grass naturally colored cow's milk.
Farmers began skimming off the cream for butter production, which removed the natural orange pigment from the cheddar.
To maintain the expected color, they started adding natural colorants like marigold flowers, saffron, carrot juice, and eventually annatto, derived from the achiote tree.
Annatto became the primary coloring agent as it doesn't affect the cheese's flavor.
The practice spread to other cheeses like Gouda, Red Leicester, and Colby, and even found its way into products like Kraft Mac & Cheese.
Besides tradition, annatto helped cheeses stand out and maintain consistent color throughout the year, despite seasonal variations in cow's diet.
While common in the U.S., New England cheesemakers traditionally avoided coloring their cheddar, resulting in the pale white hue often seen in Vermont cheddar.