1992 Topps stock variations?
 

I picked up a collection with a ton of junk wax modern FB in it. In sifting through the cards I found one with card stock that appears to be tan rather than white on the back. The difference is quite marked:


https://photos.imageevent.com/exhibi...ize/img937.jpg

Is the Elway roached or is there a stock variation known for this set?

PS: I realize that the Campen is a gold card and the Elway is a regular but that doesn't matter: out of several hundred of these I went through there were only two cards that looked like the Elway, out of a group that had been stored for at least 26 years in the same way.