That was years ago. I don't have any photos. Now that I think of it I think she was pretty young, so it could've been silver leakage or something like that. She got it around her face, eyes and on the back of her head behind her comb. Probably not the same thing as what your hens have.
Wow this is really interesting! My grandparents used to have a brown hen that started turning white from her head. That was years ago though and the hen got taken by a hawk soon after she started turning white. I think she might’ve been about a year old.