If you are inferring to it's color remember that coins are made of metal. Metals corrode (change color, etc) over time when exposed to such things as .. air .. liquids, the ground/dirt, etc. Remember, Paint would protect the metal, but coins are not painted. So your quarter looks pretty good for 35 years of circulation.
@paddyman98 Until Peter changes the categories to add a general what’s it worth and a rare and gold what’s it worth this is what we get. Reed