1965 topps joe Morgan rookie
 

I just bought a beautiful Joe Morgan rookie off of eBay. Just got it in today. I noticed that the back of the card isn't light blue but faded to a blueish gray. Everything else is fine. My question is does this happen alot in the 65 topps set or is this a counterfeit card?

Could it be an O-Pee-Chee card?

Nope, it's Topps and it is probably genuine but either faded or the result of a blue ink problem. I have a Murakami RC that is the same and I got it from an shoebox collection [literally] that I purchased direct from the guy who opened the packs when he was a kid. I hope it is a print variation rather than a fade but I cannot say for sure. I suppose one could buy a cheapo common and leave it in the sun for a while to see how it fades then compare.