Is BCM x Ameraucana GUARANTEED to produce F1 OEs?

I've heard mixed information on this, such as if the pea comb is not inherited, you won't get olive eggs. Will breeding a BCM roo over an Ameraucana hen produce only green layers?

If the Ameraucana hen is a true Ameraucana and not an EE, she will have two copies of the blue egg gene. Her daughters are guaranteed to get a blue egg gene. Since blue is dominant, her daughters are guaranteed to lay a blue of a green egg.

Green is brown on top of blue. A Black Copper Marans should have the genes for a brown egg. There is no guarantee as to exactly what shade of brown or how dark, but they should be brown. His offspring are practically guaranteed get some brown egg genes, but which ones are dominant and not recessive is a bit up in the air. It’s just the dominant ones that have an effect on egg shell color unless that hen has them too so they can pair up. Since she is supposed to lay a blue egg, not a green, she should not have any brown shell genes. So you are totally dependent on that rooster and his genetics. No guarantees there.

So you are guaranteed to get either a blue or green egg from that cross. With most BCM’s that color will be a fairly dark green, but that does not come with absolute guarantees. Still, your odds are pretty good.