Oh and I think it’s showing blue genes too, it’s so multicoloured
If it is showing blue, then it must have inherited the blue gene from one parent. So at least one parent should show blue or splash.
Many of the chicks have fluffy cheeks but this one doesn’t (not sure if all the Easter egger offspring will though?)
Some Easter Eggers will give fluffy cheeks (muff/beard) to all of their chicks.
Some other Easter Eggers will give that to only half of their chicks.
The muff/beard trait is dominant, so a chicken can show the trait while carrying the gene for clean face.
Looking at the photos, I thought the crossbeak chick did have a beard under the beak, but it's hard to be sure when the face is oddly shaped.
3 roosters are a Bielfelder & two blue Easter Eggers (unknown parents so that’s tough)
I think you can rule out the Bielefelder rooster, because all of his chicks would inherit white barring (and I do not see white barring on this chick.) If the chick has dark legs & feet, you should be able to rule out the Bielefelder rooster that way too, since Bielefelders are supposed to have yellow feet (light, not dark).
One of the EE roosters appears to have white barring as well, but it looks like he probably only has one barring gene. So he could produce barred chicks or not-barred chicks. I think he is a possible father, but not the most likely one.
I think the most likely father is the EE rooster that shows more red and no barring.
Trying to figure out combs & leg colours to eliminate too
Leg colors: it looks to me like the chick has white toes (not yellow), but the shanks might be dark (trying to be slate, but not really there yet.) If that is so, then an EE rooster with slate legs could provide all the necessary genes for a pullet to show those traits. For a cockerel, the mother would also need to have dark legs (slate/blue or willow/green).
But if the legs are light (not dark), and if the EE roosters have dark legs, then a light-leg chick would have to be male and have a light-legged mother.
For white vs. yellow skin, white is dominant. So one parent with white skin can produce a white skinned chick, and the other parent can have white or yellow skin.
For comb, I think I see a pea comb on the crossbeak chick, and also on both EE roosters. So the chick probably inherited the comb type from the father. I don't think you can rule out any hens based on comb type. Crossing the EE with single or pea combs could give a pea comb chick. Rose comb chickens often have the gene for single comb (not-rose) as well, so a rose comb hen could also be a possible mother.
Hens are many breeds- speckled Sussex, silver laced wyandotte, black australorps, barred rocks, cuckoo Maran, light/dark brahmas, Easter eggers (one splash, one blue) , red stars & black stars, production red
Any purebred chickens that are solid black, or black with white barring, can be eliminated as possible mothers. So that rules out the Black Australorps, the Barred Rocks, and the Cuckoo Marans.
Black Stars typically carry the genes to produce not-black chicks too, so they cannot be ruled out based on color.
Do you know yet whether the crossbeak chick is male or female? If it is male, you can rule out the Silver Laced Wyandottes and the Brahmas because any sons of theirs would show silver but this chick is obviously gold. If this chick is a female, then you can't rule them out that way.
You can probably rule out the Brahmas on the grounds of foot feathering, because the chick has clean feet and Brahma-mix chicks usually show some foot feathering.
That would leave possibilities of Speckled Sussex, Easter Eggers, Red Star, Black Star, Production Red, and maybe Silver Laced Wyandotte (only if crossbeak chick is female.)
At present, I can't think of any way to rule out more hens than that.
