Because the fading of dyes in color photos follows a reasonably predictable manner, i.e., cyan takes the heavy hit followed by yellow then magenta, you might try this the next time you run into a decidedly reddish cast in an old photo;
(1) open the Color Balance dialogue box in PS or its equal in your editing program
(2) add cyan to the shadows, midtones and highlights at around 30% or so( you have to judge this for yourself)
(3) do final adjust.
Fading of dyes in color photos becomes evident and objectionable at around 30% loss. Depending on what other deteriorative processes are present, simply adding cyan and perhaps a smaller amount of yellow can work wonders. The attachment shows the result of adding cyan at 30% to shadows, 24% to midtones and 18% to highlights with no other tone/color etc. adj. done. Tom