Really? Didn't you carefully read the explanation? The color change is due to Environmental Damage. I am just saying that some of us when we go detecting we find these types of coins that were buried. Even if your at the beach and you kick the sand around, one of these off color Nickels can pop out.
I do metal detecting and I get coins (nickels,dimes, quarters) that look like this all the time from being in the ground, they are worth face value.