I always thought that the 2.50 chip was named because it was intended to be “snapped” right back to the dealer as a tip for dealing you the blackjack. I have played in some casinos in Europe where this is practically a rule. If you don’t give the dealer the 2.50 as soon as he pays you, you will get an icy stare. Of course, I bet odd amounts because I want the snapper, so imagine the dealer’s surprise when I threw him a 5 euro chip instead of the 2.50. Many casinos now use a 12.50 for a snapper because minimum bets at blackjack have gotten higher, or are in different currencies. I have seen this in South Africa, Zimbabwe, and once in a while in Europe. I have also seen 2500 chips used as snappers, for instance with the old Greek drachmas. As for the two states that require pink snappers, one of them must be New Jersey.