[M1903A1]

Having attended more slide/movie shows than I can count (as a train buff), I remember case after case of Kodachrome images that were fifty or more years old yet still looked like they been shot yesterday, while Ansco or even Ektachrome images--that were only twenty or thirty years old--were washed out and turning red or blue.

The secret of Kodachrome, I've been told, was that the film itself was three separate layers of black-and-white emulsion with filter layers, that responded according to the three basic colors. The color dyes themselves were added during the development process, which I've heard involved as many as fifteen different, tightly-controlled steps.