Rock rooster with mutation? Maybe?

[Frazzemrat1]

Could it be made true through a lot of breeding

Yes. You could start a selective breeding program for a project type.

 

[Ian_knight]

Yes. You could start a selective breeding program for a project type.

I might try it

 

[JB8907]

Not a male trait.

I only have 2 black birds. Both are black marans. 1 hen and 1 roo the too had the green sheen and the hen has nothing. Not arguing your facts just stressing how things are never 100% certain.