There is a conflict between the spelling in the thread title and the first sentence of OP's post, which asked about crossing a TRUE "Americana." @Ridgerunner 's explanation is based on the assumption that since true was used, the OP has a true AmerAUcana black hen. But even if the hen is an Americana i.e. Easter Egger, one shouldn't assume she lays green eggs. I've had MANY EEs that lay blue eggs. Two years ago I actually took the step of having 10 EE roosters DNA tested to learn if they were homozygous or heterozygous for the blue egg gene. (6 tested homo, 4 tested hetero.) I did this because after crossing EEs to many other brown-laying breeds through the years, I wanted to make sure I didn't lose the blue egg gene.title is Americana, not ameraucana. This would suggest a green egg.
Which leads me to this:
When I read this, I immediately thought of @Ridgerunner even before seeing they had posted here, the reason being I once stated that exact same info on a thread several years back. I had read that info on a non-BYC site, and had no reason to doubt its validity. Ridgerunner corrected me with an informative post as to why it's not that simple, and I've also since seen other BYC genetics experts confirm it. I think I've gotten too old to learn all the intricacies of bird genetics, and so choose to accept the validity of info stated by BYC genetics experts, even though I may not always understand why.If you bred one of the resulting roosters (son) with the original hen (mother) **which is completely acceptable in the chicken world** you'd end up with each having a brown and a blue copy and this
50% green egg layers
25% blue layers
25% brown layers.