Cardinals get their trademark red plumage from their food. While they are mostly granivorous, or grain and seed eating, cardinals also eat insects and a wide variety of fruits like wild grapes, dogwood berries, and mulberries. These fruits contain carotenoids that can create the reds, oranges, yellows, and pinks found in avian feathers.
Not all Northern Cardinals are red—some can be yellow! Yes, different from the actual Yellow Cardinal, there can also be a yellow version of the Northern Cardinal. Cardinals with an orangish-yellow hue have been reported for decades. This deviation in coloration is caused by agenetic mutation that results in a bird missing the enzyme that converts yellow pigments in their food to red. This mutation only affects an estimated one in a million birds, so seeing a yellow cardinal is truly a once-in-a-lifetime event.