Superman Vintage Kryptonite Rocks Color Key. From the Pop Arts Archives. Pop Arts produced the famous 'Kryptonite Rocks' back in the 70's in Medina, OH. After filing bankruptcy in the early 80's, its inventory and archives were liquidated and auctioned off. This Final Color Key was part of that auction. It is the only one known to exists. As you can see it is several different prints that overlap to show the final colors of the box. It is being sold on consignment by the original buyer from the auction who has had it all these years. He will consider all offers on this rare 1 of a kind item. Please email with any other questions.