Hahns don't naturally have black like that, no
Feathers that grow in like that are stress marks. Can be nutritional deficiency, but also can be from anything that caused the body to temporarily take nutrients away from growing a feather. An illness, high stress situation, etc.
Feathers that turn black after growing in are from bronzing. Green in a lot of species is created by little ridges in the feathers that cause light to reflect as green. When the feathers are worn, the illusion is interrupted.
Regardless, a few black feathers from either reason wouldn't immediately concern me. If your bird starts getting more black, then you obviously want to be sure you know if it's on new feathers or not so you can better understand if it's time to worry.