I don't understand why green was not a very popular color among the Vistalites produced by Ludwig in the 1970s. Some collectors claim, that Mr. Bill Ludwig said, there were only about fifty green sets made in the 1970s. I have my doubts about that number, but we know there are a lot fewer green sets than clear or blue. The darker green and red sets just didn't  sell as well as the clear and lighter colors. The amber color got a big boost from John Bonham's using them on tour with Led Zeppelin.