This is a sad admission, but an accurate caveat from mnemosyne.
If you can test a bit of a sheet first, there, at the buying location, do it. Last November, at Berry & Homer (major past processor of color in Philadelphia) I was able to do just this in their darkroom on seven 100 sheet boxes of Fujicolor paper and my tests proved that the paper, although about eight years old, was still 90% perfect. Restrainer will complete the job, but how to store this paper for the future is a conundrum.
Unfortunately, unlike with B&W papers, ability to get white from older stock is very limited with restrainer in the color developer and absolutely nonexsistent from attempting a post-blix Farmer's reducer, as there is no silver left to reduce! When the white starts turning (first, yellowish) you have limited ability to turn that back to white. (How I would LOVE to find a chemical that would reduce that base density back to white, evenly throughout!)
Again, unfortunately, our eyes tend to 'get accustomed' and forgiving towards that yellowing, but, when a superior print is placed alongside, the revelatory difference manfests. Some would incorrectly posit that we simply use a bit more yellow in the filtration in order to combat that tendency. But that is false advice, since when we NEED WHITE in the print, NOTHING will bring that about. A general lowering of print contrast is the result.
Bad color paper is best used for either proofing (even that will mislead color correctness ability, though), or 'artistically creative' attempts. Sometimes a 'noir' print can be effective. Think, try, experiment: Sometimes using what we have leads to creativity far outreaching that obtained with 'perfect' materials. The human mind is multifaceted and needs to be challenged, (even with one as old as I am). - David Lyga