Most old school Super NES owners know the drill. After a certain amount of time one half of the system turns a yellow-green color. Just the one half, not the whole thing, and it doesn't matter how well you take care of it. It's one of the great game-related mysteries of our time, but Vintage Computing and Gaming has just solved it:

Most plastics typically reflect the majority of UV light that hits them. However, if there are trace elements of catalyst residues (chemicals used in manufacturing of the plastic), such as if the manufacturer doesn't get the mixture quite right, then the residues present in the final plastic will absorb UV and drastically accelerate the degradation process.

In the case of the SNES plastic, however, the trigger of the oxidation process is clearly not UV light, but simple and unavoidable exposure oxygen in the air over time... Since two different batches of plastics had two different aging results... then there must have been a difference of additives between them.

Unfortunately there isn't anything you can do about it, as the problem is an internal chemical reaction, and you would essentially have to destroy the system in order to even attempt a restoration. Green or gray, the SNES works just fine, so ignore it and get back to playing Chrono Trigger.

• Vintage Computing and Gaming - Why Super Nintendos Lose Their Color