I received a family member's rptv (lcd I think), and parts of the screen show various tints of yellow. It's not very noticeable, but if it's fixable I'd like to know how.

These spots don't appear to be any for of burn-in, the don't follow any perceptible pattern, and my first thought was that the screen was starting to rot from age. I've been searching for more information abotu screen rot, but haven't found anything that would make me more/less sure about it.
It's not worth me keeping it if it requires replacing the entire screen, has anyone had the same problem and found a solution?

I will try to take a picture tomorrow.

You need to tell us the manufacturer and model number. I don't think it is screen rot, though.