The story of Mannes and Godowsky is from an issue of Invention and Technology of about 20-25 years ago. I have a xerox of the article, but since I couldn't find it quickly, I wrote from memory. I think both their first names were Leopold, but to be sure it needs to be double-checked.

Color couplers, dyes which are light sensitive, are a German invention of c1910 -- Germany of the era was /the/ dye and chemical manufacturer nation. The Lumiere Brothers (France) used dyed starch grains. See [en.wikipedia.org] I have two of these "slides" of my aunt, taken about 108 years ago, along with the box. The have a charming, pastel, other world quality, and the grain is so coarse, they look sandy. The emulsion speed was very slow, making for two or three second exposures.

I also might add that color photographic processes (slides, color negatives, prints) are three color, while non-film color printing (magazines, lithographs, and your inject/laser printer) are four color. Black is added to give the image a crisp look. Some of these printing processes use more than four colors.

The best printing process is, of course, Gravure, also called Roto Gravure. [en.wikipedia.org] The ink image is actually a relief map of sorts, and if you've ever seen a Gravure print in the flesh, you'd realize what junk the half-tone process produces. The best half-tone work I've ever seen was done by the late Al Rose.