I agree with Les here. I too read the article by Ctein (in the magazine "Darkroom Techniques" ????), and although I usually "hung" on his every word in Camera and Darkroom, this one didn't make a whole lot of sense to me.
There was another "writing" in C&D about "environmental conditions" and RC paper longevity - where a significant cause of image degredaton was attributed to phenols "out-gassing" from surfaces freshly painted with oil-based paints. C&D recommended - strongly - that latex paints should be used in all galleries.
As for color ... certainly, in the past, color prints *would* fade - but that may not indicate the permanence of modern materials. I have Agfa "Signum" color prints safely tucked away in my portfolio that have yellowed significantly over the years. I also have Ilfocolor prints hanging on the walls of my studio (incidentally, latex painted) for six - seven years with *no* degredation at all.
I would love to see definintive, really coherent information about all this.