Oops I forgot to add the blue CM was out crossed with an Ameracauna so was het for the blue egg colour. Sorry my bad
That changes things. Details! Details! You really made my post a lot longer with that little bit of information about the Ameraucana.
Anyway your Easter Egger rooster is split for the blue egg gene assuming that was a true Ameraucana pure for the blue egg gene. That means he will randomly give one blue egg gene or one not-blue egg gene to his progeny. So in theory half of his pullets will lay eggs based blue. As you probably know green is just base blue plus brown.
Since he is a rooster and doesn’t lay eggs, you don’t know what color his genetic make-up will contribute to the mix. A Marans should lay really dark eggs, but the eggs are not always as dark as they should be. That’s why they have a scale to measure the shade of Marans eggs. Since there are so many different genes that contribute to the brown coloring they are not always as pure as you might expect. Still, you would expect him to have inherited some pretty dark genetics from the Marans parent.
Not so at all from a true Ameraucana. They lay blue eggs so they are not going to contribute much at all to a brown shade. This is chicken genetics so it gets complicated even trying to describe it. There is a gene that cancels out some brown, so it is possible a true Ameraucana could have a gene that contributes to brown but if they have that other gene it gets canceled out. It’s possible, but it is pretty safe to say the Ameraucana contributed genetics that would make for white eggs if the blue egg gene were absent.
So your EE rooster has the genetics that are split for brown and white eggs, ignoring the blue shell gene. Half the gene pair says brown and probably dark brown. Half the gene pair says white. The genes from that gene pair will randomly be passed down to the offspring. You are going to have a really mixed up genetic cocktail passed down to his offspring, each one could be really different, anything from no brown added to a really dark brown added. Most will be somewhere in between.
Let me complicate it a little more. You might want to grab a Tylenol. Not all RIR hen lay eggs the same shade. They often have a mix of brown egg genetics too. You’d think that you would at least be consistent on what you get from her, but no. It’s quite possible she could be split for some of those brown color contributors. If they are not homo at that gene pair it is just random which gets passed down.
To make it worse for both the EE and the RIR, some genes are dominant and some are recessive. If some of the brown egg color in the parents or grandparents is coming from recessive genes that have paired up, you would lose that effect in future generations if they don’t happen to pair up.
Bottom line is that you don’t know what you will get from your mix. If you hatch a bunch of pullets from that mix you should get a real rainbow in your egg basket. Odds are a lot of them will be fairly dark brown or dark green, but don’t be shocked to get some that are almost white or almost blue.
For what its’ worth, I mixed Ameraucana in my flock of brown egg layers. In the first generation I got some eggs that were almost blue and some that were really dark green. In the second generation I got some similar light or dark blue/green and also got some of various shades of brown, some dark, and some that are almost white. I guess you would call them tinted. It makes for an interesting egg basket but it is really inconsistent.
