Biliverdin creates a blue or green hue, as seen in the eggs produced by Araucanas and Ameraucanas. Egg color is a trait firmly rooted in a chicken’s genetic makeup. The gene Oocyan, present in ...

The deepness of the blue in the eggshell depends on the concentration of biliverdin. Sometimes the color might range from a greenish-blue, or a paler blue and every color in between. Here are 15 ...