I just took 4 hens out of the breeding pen because I am not hatching as many anymore. However, mine are beginner flock so I am crossing black cuckoo hens with Golden cuckoo roo. I have only one Golden cuckoo pullet in there and she isn't laying yet.
All the chicks are still only a few weeks old so I can't say what they will be like. Some are hatching out black and some are hatching out gold.
All my black cuckoo girls I have/had in breeding have gold necks. I have about 120 eggs hatching or set in the 'bator. The next few weeks will be interesting.