I found these at the convention this year. Chipco metal tokens coated with enamel. I'm not sure what they were used for. The babies are quarter sized. The reverses of all three colors are like those shown on the white ones.

These Colorado tokens apparently are pretty scarce and the set went for around $100. Anyone have the later years? I see in Chipguide there are at least two more years available.

By the way, these were in vinyl flips, probably since 1996, and they had bled noticably into the plastic. It's not only Chipco chips that had the color migration problem.