My ZRX 100 was green, but I kept it next to my ‘81 Kawasaki GPz 1100, which was red. I used to call them the twin devils, the red devil and the green devil. BTW, the GPz was much faster off the line than the ZRX
I got a used ZRX1100 and the guy had a yoshimura pipe on it that was loud but made it run worse than the stock pipe, which I re-installed. I bought a jet kit and it really woke the motor up with the Yoshi pipe. Fun bike. Many times I wished I kept it.