Are there any methods to remove the brownish discoloration from NES/SNES cartridges? I've seen people use that retro-bright mixture on consoles before, but I'd be a little wary of what might happen if I got that on a cart label. Any ideas?

lol try painter's tape. hahahah j/k.

I always thought the discolouration was caused by a fire retardant material in the plastic which turned yellow from uv exposure.
Isn't that irreversible?

Yea retro-bright is the stuff you would have to use. I have plans to try it on a color dreams game, because in retrospect it should turn the cartridge back to its original blue color. As you suggested thou, the label would need to be covered up on both sides so you don't get any of the gunk on it. I would test it in a crappy game first.

Retr0bright should NOT be handled by anyone not willing to exercise extreme care as it is a chemical mixture.
The results are amazing from what I've seen though

I guess that's what I will have to use. I tried Oxi-Clean alone and it didn't work.

the only cart-based games I collect are snes and genesis. The sega carts are black so it's no biggie. For the SNES carts, I realized that only the back portion gets discolored, so I just buy cheap sports games and replace the back since they're all identical, excluding carts with coprocessor chips.

Hold up I just remembered something... a guy on youtube removed discoloration from his 'Ole Yella SNES console with a cocktail of oxy-clean, hydrogen peroxide (1:1 ratio), and cornstarch to make it a paste. coat the plastic and leave it exposed to UV light for a few hours. Here's the link:

i know this thread is really old, but i just got a very discolored baby boomer from ebay and i would love to try to restore it back. did you ever end up trying this or did anyone else?