This is amazing. Almost a hundred years ago, Russian photographer Sergei Mikhailovich Prokudin-Gorskii was using a three-exposure camera to take what amounts to the red, green, and blue channels of a photo. He then projected the three exposures through their associated filters and, well, you can see the results:

“Color film was non-existent in 1909 Russia, yet in that year a photographer named Sergei Mikhailovich Prokudin-Gorskii embarked on a photographic survey of his homeland and captured hundreds of photos in full, vivid color.”

Full article: Color photos from the World War I era