It's not easy, but you can use Photoshop to restore faded prints and slides of all kinds.  In this example, I've taken a badly faded Ektachrome slide almost 40 years old.  I worked to set the black, white, and grey points, and then used curves and levels to reduce the yellow masking and bring out the remaining colors.   You can save this process as a macro (called "action") and process entire rolls with the same corrections.

It's not perfect, but it's alot better...