Dufaycolor

John Joly independently reinvented the concept in 1894 and attempted to commercialise it, but the first successful product based on this idea, the Autochrome plate, did not reach the market until 1907.

A very thin coating of collodion on one side of the film base was dyed blue, printed with closely spaced fine lines using a water-repelling greasy ink, and bleached.

In the case of still photographs, the result, known as a diapositive or transparency, was usually viewed directly by means of a backlight, but it could also be bound up between cover glasses or mounted in a small frame for use in a projector, in which form it was commonly called a slide.

Less saturated tints, and non-primary colours such as orange, yellow, and purple, along with neutral grays and white, are reproduced by various proportions of red, green, and blue light blending together in the viewer's eye due to the tiny size and close spacing of the individual elements.

Typical modern LCD video displays work similarly, combining a backlit black-and-white image layer with an array of hair-thin red, green, and blue vertical filter stripes.

Louis Dufay's interests were purchased by British paper manufacturing firm Spicers in 1926, which then funded research to produce a workable colour motion picture film.

[citation needed] Dufaycolor was used in only two British-made feature films: the two colour sequences in Radio Parade of 1935 (1934), and the all-colour Sons of the Sea (1939), directed by Maurice Elvey.

Dufaycolor remained the only successfully implemented additive film stock for motion pictures until 1977, when Polaroid introduced Polavision, a system for making and viewing "instant" colour home movies that proved to be a spectacular commercial failure and was soon discontinued.