Last note and I'll let the experts take over:
Ted found that the "Apple Green" Sovereign backs were exclusive to the 350/460 print run. Here's the link to the thread.
http://www.net54baseball.com/showthr...overeign+apple
During this same print run ALC dropped the frame from the American Beauty backs.
Are the two related, I don't know.
These things lead me to believe that ALC was very conscious of what they were doing in regards to the backs including the colors they used to print them. After all to ATC the back was more important than the front.