Should I be concerned???

[Littledinostaurs]

Yes. I'm not sure the exact science behind it, but after the old scale falls off, the new scale underneath is the regular color.
Of course, I'm not sure if this is what's going on with your chicken, it's just a possibility. I can see if I can get any pictures of my chickens feet if they're shedding any leg scales once I'm home today.

Ok thx