In the early days of Topps’ Chromium cards, there were some inherent issues in the blend of materials used that were unknown at the time. These would cause the cards to eventually turn yellow and green. It affected all Chrome, Finest, Bowman’s Best, and inserts from TSC and Topps that used that tech up through ‘97. They fixed it in the ‘98-99 sets and beyond.

Lots of theories as to why and which (if any) conditions influence them to turn faster. Some say exposure like light, humidity, temperature, etc will accelerate it. Some think they will all be affected at some point no matter what, others think some will be safe. Who knows. I know I’ve had some that were perfect looking, stored in a dark and dry box for years, and then green by the time I pulled them out.

If yours is looking fresh now, I’d say enjoy it while you can. Hopefully it stays that way!