I’m NOT at all saying that buck has any staining but I am saying that colors/lighting/pic quality etc can sometimes be very deceiving.
The pics below I took last year I had the settings all wrong on my camera on a real damp day. The two bucks some would say showed black all down their legs but in reality with my naked eyes and binos they didn’t look like that. The one buck was killed and had NO stained hock at all much less down his leg and that was unusual. He also scored 160 and doesnt look it in pics at all(be careful of pics.)
I would apologize for the crummy pics, but that’s the point of my post.
Of course, the OPs pics would have to be the opposite to apply, with them being so washed out.