The Circus Circus "Good Only" chips came in several varieties. There was a long discussion on the chip board a few years ago on why they had the different colors and how they got the colors. One interesting theory was that they were colored with marking pens in different patterns and each pattern was given to a different hawker to pass out on the street - that way they could track who was doing the best job of steering business onto the casino floor. I don't think anyone had a definitive answer.