Probably not an error, but it stuck out like a sore thumb. It has almost a gold hue. Some dingus painted over the penny perhaps? At an angle it doesnt have that shine
It looks to be gold plated and then Circulated Heavily. May have been in a joke birthday card. I got you some gold for your birthday.
It could be 1 of a Kind - Value is in the eye of the collector...I tell my wife that when she tells me to throw out my old video game carts... I'd keep It...spend it only if you need a penny
LoL - Atari - I 'm sure my excuse wouldn't fly - But She bought me the Brand new 2600 for Christmas in 1980