Quarter color of penny 1965, 1999 Pennines color of a dime

Quarters, like cents (Britain has pennies, not the US) are made mostly from copper, so it logically follows that sometimes when they suffer environmental damage, both coins oxidize to a similar color. As for the light colored cent, it could be that the copper coating has worn off and is showing the underlying zinc. However the features are strong so I'm thinking it might also be a coin that somebody coated with zinc chemically in a science activity or something. What you should be asking about is the mercury dime, that's the one coin pictured that's made of silver, and it's worth a couple bucks.