While there is some variation in eggs once they are cracked, the different yolk colors and flavors have nothing to do with the shell’s external color. Chickens fed the same diet will have very similar eggs – on the inside. Once cracked, eggs pretty much look alike. I was shocked to see brilliant orange yolks in our early chicken days – we had been giving them cantaloupe, sweet potatoes, and other colorful foods, resulting in a vibrant orange yolk, regardless of the external shell color. Any impact on egg yolk color comes from your chickens’ diet, not their shell colors.