[Is Kodachrome the only alternative to B&W for archiving?

In another thread the topic of archiving came up, and from what I can gather the only way to really archive color (more than 100 years) is with color separation negatives on film or glass plates. I had hard time accepting this but I have not had the time to see how the museums and universities are achieving their color collections. Anyone have any knowledge?

I have 35 year old Kodachrome which have held up very well, Extachrome, Agfa, and GAF from time frame are starting to fade, the GAF very badly.