[stefan4u]

My older color paper does lack clean whites, there is a slight amber touch, but overall behavior and contrast is OK.
Up to a certain degree you can compensate the aging/staining/fogging a bit through slightly decreased development time / decreased temp. in conjunction with slight overexposure. If this will not help enough I consider my paper as “gone”…

Maybe 2 more ways to explore,
You may add some benzoetriazole to the color developer, this is not very common in color chemistry and will force you to adapt filtration and exposure a bit. Overall Contrast may suffer too. But actually this is the way DIR couplers in color negative film are working; they are releasing benzoetriazole (or analoges) during development to decrease D.max selective in the higher densities.

Low doses of sulfite will reduce color coupling / contrast too

These variants are considering only slightly higher D.min /amber touch/staining in unexposed regions of color paper, which other wiles shows still good contrast and color reproduction. If fogged by light or mistreated by wrong storing temperature this will not help…

Regards, Stefan