The 1980 version is listed as light blue with purple stars. The 1981 version is listed as dark blue with purple stars. I think I have both versions but I'm not sure. Below is a picture of my chips. The chip in the flip is what I think is the light blue version, 1980. The chip with no flip is what I think is the dark blue, 1981. It's hard to tell if there is much of a difference in the blue, but the stars are definitely a darker purple color on the chip on the right. The chip in the flip has lighter purple stars. Can anybody help me out on this? I would really appreciate it. I also have the 1983 version with the Navy colored stars, but that one is very easy to differentiate. Thanks