Since I am not a breeder, here is my layman's understanding of the situation:
Greenfire crossed Chocolate Bantam Orpingtons with Black Wyandottes to get Chocolate Wyandottes that breed true to color. All offsprings of these turn out to be Chocolate Wyandottes.
Wheres some people have the Dun gene Chocolates (resulting from the work of a US geneticist) . A cross between a Dun Chocolate and Dun Chocolate can result in 50% Dun Chocolates, 25% Black and 25% Khaki.
The eggs I have are from the Greenfire line so they should be Chocolate. Not feather sexible or color sexible at birth.
Correct me if I am still wrong.
Not just GFF made that cross. I know Jerry Foley did it too.