Chickens comb turning black but seems healthy?

[Holly_baxter]

There may be some ayam cemani genes in those chickens. Here is a picture of one:
https://www.amusingplanet.com/2014/08/ayam-cemani-rare-chicken-breed-that-is.html

Oooo yes they are beautiful!

 

[Holly_baxter]

Maybe your hen just really like The Cure and Radiohead and is going through her emo phase.

But that aside, I think the answers with genetics as the cause are probably right here.

yes I agree