LEG colour dominant/recessive ?

[Minky]

yes, I had one Buff Orpington. " Big Red" but I honestly can't recall if she was alive when these chicks were born, but her son RUSTY is likely the dad of the first two hens (Little Gold Coins and Queenie).
Would that work??

Otherwise- one way to tell for sure, is I wait until they are laying eggs, if the eggs are blue- then the Cream Legbar rooster fertilized them, and if the eggs are olive then the BCM fertilized them, and they are descendants of the Buff Orpington Big Red.

Correct? Rusty is below. (his comb froze off in 2019). Rusty's dad is a CLB, but his mom was either a Buff Orp, Welsummer, or Barnevelder.

 

[Amer]

yes, I had one Buff Orpington. " Big Red" but I honestly can't recall if she was alive when these chicks were born, but her son RUSTY is likely the dad of the first two hens (Little Gold Coins and Queenie).
Would that work??

Otherwise- one way to tell for sure, is I wait until they are laying eggs, if the eggs are blue- then the Cream Legbar rooster fertilized them, and if the eggs are olive then the BCM fertilized them, and they are descendants of the Buff Orpington Big Red.

Correct? Rusty is below. (his comb froze off in 2019). Rusty's dad is a CLB, but his mom was either a Buff Orp, Welsummer, or Barnevelder.

Yes.
That sounds about right, except that the chances of your hens passing columbian and ginger together are slim. So I still suspect the Legbar of responsibility. The eggs would be green though, not blue.

 

[Minky]

Ok... well We will know for sure in a few months! The eggs were blue for sure.
I'm excited to see the outcome. Thanks for your sleuthing help!