Oh, another thing I have observed, I think I told you about this before, when a white loses part of their tail, the fur grows in almost pure black at the tip. I had a gray, with a white brother and mother, who lost a small patch of skin on "bridge of nose" for lack of a better description, and it grew back almost pure white! Unfortunately she rejoined the food chain shortly after release so I couldn't track if it would stay that way after next molt. There also appears to be seasonal variation on head patches of whites ranging from "gray squirrel" coloring to pure black on same squirrel, particularly Snowflake, having watched over 5 years.