Speaking from "my cave".
Mauro (and others). If you will place your color variation PB chips under a uv light source (blacklight) you will discover that the color variation have to do with the chip being u.v. tagged ... especially so on the two $1 blue variations and the brite orange $100 and dark green $25 chips.
With the large numbers of PB chip variations currently available to examine ... this is a new area of specialization that a few A.C. collectors might want to explore. I've personally spoken to a former Bud Jones sales rep over the weekend and he claims that these u.v. variationns were due to PB chip re-orders that was introduced after the original un-tagged chip shipment.
