Answer: Marigold Petals

Egg yolks derive their color from carotenoids in the plants and feed the chickens consume. American chickens eat diets high in carotenoid-rich yellow corn and tend to have yellow egg yolks where as many African chickens are fed white corn (which is low in carotenoids) and tend to have very pale egg yolks.

When farmers want to crank up the sunbeam-yellow shade of their chickens’ yolks, however, they turn to natural means. Consumers strongly dislike unnatural ingredients like dyes or additives in their eggs, so the farmers stick to a very natural solution: feeding the chickens feed laced with natural sources of carotenoids. Among the most frequently used materials are marigold petals which help load the chickens up with the very carotenoids that give the marigolds their bright color.