Egg color has little or nothing to do with plumage color. The dominant \"O\" gene that causes blue pigmentation in the eggshell is not on the sex-linked chromosome, so males and females both carry it or lack it. The multiple genes (up to 12 of them I\'ve heard) that cause brown egg shells are inherited independently of the O gene, so chickens can be hetero or homozygous for both. The problem is that brown pigment changes the blue to various shades of green. Thus the challenge is to get rid of the many genes that cause brown color on the egg shells. Yes, brown shell chickens were crossed in to get proper plumage colors and that is why some, maybe many, strains of Ameraucanas do not lay a true blue egg. To correct that issue is the challenge that lies before us. I personally keep no bantams that lay green eggs unless it is a special project I\'m working on, and those are eliminated as soon as possible. In the future I would hope that folks would be more judicious in their choice of outcrosses in the attempt to create new or improved varieties.
