Technicolor wasn't the only company working on bringing full color to the silver screen. This is an example of Eastman Kodak's two-color Kodachrome process of the 1910s and 20s (not to be confused with Kodachrome slide film). This particular sample appears to be from around 1929. Left to right: (1) original negative with one color record above the other; (2) duplicate positive of one of the color records; (3) duplicate negative of one of the color records (this would have been done on duplitized stock with emulsion on both sides, one side for each color record); (4) after the same duplicate negative has been bleached and tanned to remove the silver and harden the gelatin; (5) one side of the duplicate negative is dyed green; (6) one side of the duplicate negative is dyed red; and (7) when combined on either side of the base, the two dyed images create a reversal print. © 2014 Smithsonian Institution; photo by Jaclyn Nash.