An egg's shell is determined by the breed of the chicken. Not all chicken eggs are white or brown; some chickens, such as the Ameraucana and the Araucana, produce blue and green eggs. The color of the yolk, however, can be affected by the chicken's diet. Feeding certain dyes to chicken can cause them to lay eggs with varicolored yolks.
An egg's shell is determined by the breed of the chicken. Not all chicken eggs are white or brown; some chickens, such as the Ameraucana and the Araucana, produce blue and green eggs. The color of the yolk, however, can be affected by the chicken's diet. Feeding certain dyes to chicken can cause them to lay eggs with varicolored yolks.