The first time I saw this in a chick (Maran Black Sex Link) I thought for sure my Ayam Cemani broke out of his Pen and got into the Cuckoo Maran pen. Nope, the Father was a Black Copper Maran.
I have had non Fibro chicks who had black Combs and Waddles until they matured. My Maran Black Sex Links were like that as well as a few other mixes.
I have also had bright red combs on chickens that were descended from Fibro birds who ended up with dark or grey meat when processed. I...