Below are scans of 2 chips that have been stored in the 2½ x 2½ cardboard holders for many years in the red storage boxes. They seem to be turning from white to light brown. At first I thought that it may be from cleaning them in the past. I can't be sure about the Majestic Star chip but I know for a fact that the canceled chip has never been cleaned. This only seems to be happening to clay chips in the red boxes. I have many chips stored in the cardboard holders in Cowens pages and I have not found any becoming discolored. I have not found any non-clay chips with this problem, no Chipcos, ceramic, plastic etc. Any thoughts as to what might be causing this? Any help would be greatly appreciated.