I don’t have a good handle on Cream Legbar genetics. I know they are barred and I think they are gold, the barring dilutes the red to make more of a cream color, but I’m not sure. I don’t know what else is there. The BCM should be Birchen, which is fairly dominant and contains black, so you probably will get chicks with a fair amount of black or blue.
You have a way to tell sex. The barring in the CLB hen and no barring in the BCM means any barred chick is a male and any not-barred chick is female. I don’t know how well the head spot would show up on those chicks at hatch, but if you look at their darker feathers you should be able to see barring on the males by now.
About half the chicks should show blue, half black. A Blue Copper Marans has one B/B/S gene and one that is not-B/B/S. That gene is passed down at random so each chick has a 50-50 chance of having either one. That does not mean half the chicks will be Blue, that depends on the odds. But if you hatch enough you should have some of each. Blue only acts on feathers that would normally be black. It does not affect red or white feathers.
The CLB hen has two copies of the blue egg shell gene, so all pullets should lay colored eggs. Not all Marans have the genetics for really dark eggs and the CLB hen has no genetics for dark eggs (See next paragraph for a qualification, there is always an exception in chicken genetics). There are a lot of different genes that control just how dark the eggs are, some dominant, some recessive, and some that only act if something else is present. What shade of green the eggs will be depends on how those genes go together. In general, if the BCM rooster hatched from a dark egg you can expect to see fairly dark green eggs, but sometimes you get some real surprises.
Another complicating factor is that CLB hens do not have to lay blue eggs, green is also allowed. The latest I heard the CLB is not a recognized breed in the USA but at least one group working to get them recognized are suggesting both blue and green eggs be allowed. So if your CLB hen is laying green eggs instead of blue, your odds of darker eggs go up.
With egg shell color you basically have to wait and see. And different pullets from the same parents will often lay eggs with different shades of green. It just depends on how those random genes go together.
These are showing barring on the feathers and pretty little crests already. One, though, is black with a beautiful crest. I do hope it is a pullet! My CCL girls lay beautiful blue eggs. The BCM did hatch from a chocolate egg, so perhaps the crossed hens will lay a dark olive. I have 3 girls who were crosses of my BCM roo and a pretty Blue Ameraucana. You're right they are 3 different shades of green. Thanks for your thorough explanation of the genetics!!
