When this thread started back on Tuesday I read it with only an academic interest since breeding a single-comb blue/green egg layer is not a project I'm particularly interested in.
It became something more than academic when I gathered the eggs that night! I have four layer tractors and one of them has nothing but Rhode Island Reds in it, but for two cross-breeds we hatched out last Spring. By their size, shape, and coloring I reckoned them to be a Buff Orpington and Rhode Island Red cross as I have a Rhodie cock bird and a couple of Buff hens in the yard we took the hatching eggs from. So I was considerably surprised when I gathered the eggs Tuesday night to find a green pullet egg in their box.
Now the yard we took the hatching eggs from does have two EEs in it. One's as white as snow with green legs. The other is the color of a perfectly toasted marshmallow - gold over white - also with green legs. Looks like perhaps a Buff Orp in her background somewhere. Both originated from Ideal so no idea what their make up is other than being EEs. It may be she produced the pullet that laid the green egg in the tractor the other night.
What makes this interesting is that neither of those cross breed pullets in the Rhode Island Red tractor have dark legs and both sure look to me like they have single combs. They haven't really started laying yet though, just that one egg so far, so their combs are not very developed yet so it may be that she just has a really bad pea comb. But it sure looks like a single comb to me. If I get another green egg out of there I'll take photos of both birds and let y'all decide.
Now I'm kicking myself for selling the two cockerels that hatched with them that looked just like them, but who knew?