Color Photography

The first practical photographic process in color, the Lumière Autochrome, used the additive colors of red, green, and blue. The Autochrome plate was glass coated with grains of potato starch that had been dyed these colors. The image is exposed to light and developed directly on the glass, so there was no negative from which to make copies; each Autochrome was unique. Because they were glass transparencies, Autochromes were much less useful than paper prints.