I apologize for forgetting the story behind these. I bought some a number of years ago, asked about them at that time, and I think Noelle knew the story behind them.
If memory serves it had something to do with Jack getting a deal on blue paint in '84 or '86, but people didn't want to buy the blue ones. They thought the heads were seconds, the quality wasn't as good, or something to that effect. So Jack had to go back to green after less than a year of using blue.
If someone could refresh my memory with the exact details, I'd appreciate it. Thanks.