while checking out my unc details collection to see if they are actually unc. i spotted this, at first thought scheeech scratches on the fore head. but anyway they aren't. and am wondering would you expect the grader at least mention it. color looks ok to me, in other words, i cant tell how its altered.
For several years now I have seen gold tone added to cents for enhancement and collectability. When the tone wears off due to circulation it looks similar to what that cent looks like. That was my first and only thought about it.