Piebald Shatter?

Is this something that is out there? I noticed with my guy today when I was looking around his face and neck that he has gray patches. I"m trying to see if I got a pic of it or not when I had him out earlier today. Or is this something common in piebalds?

It's typical of the morph.

Grey side neck :)

My female pied has it too. Almost like she dipped her chin and side of her neck in ashes. I thought it was dirt at first and I tryed to wipe it off but it is part of her coloration.