The catch is that friendly foxes don't look that foxy anymore; friendly zebras might lose their stripes at which point they kinda look like donkeys

That is entirely possible of course. But if that was the case, you could get a hell of a paper out of it by proving the genes responsible for coloration were tied to domestication.

I'm afraid Darwin already published on how domestication syndrome involves pleiotropy in coloration changes, especially to piebaldness (which did indeed also happen to some degree in the domesticated foxes despite being selected solely based on behavior), so he has priority there by 2 centuries or so.

They look a lot like wild foxes to me: https://en.m.wikipedia.org/wiki/Domesticated_red_fox