“In 1873 Dr Vogel discovered that by adding dyes to the sensitive material, its sensitivity could be extended, so that it would record green as well as blue. The new ‘orthochromatic’ plates were available commercially from 1882. The first really efficient dyes, extending the sensitivity of the photographic emulsion to all visible colours, were not available until the early years of this century, but by the late 1890s photographic materials could be made sensitive to orange and red-orange light, making colour photography practical.”
(Coe, Brian (1978): Colour Photography. The First Hundred Years 1840-1940. London: Ash & Grant, pp. 116)
Original Technical Papers and Primary Sources
Vogel, Hermann Wilhelm (1873) In: Photographische Mittheilungen, Dec. 1873, 10,117, pp. 233-237.
Coe, Brian (1981): The History of Movie Photography. Westfield, N.J.: Eastview Editions, on p. 116.
Hopwood, Henry Vaux (1915): Color cinematography. In: Henry Vaux Hopwood: Hopwood’s living pictures. Their history, photoproduction, and practical working. With classified lists of British patents and bibliography. London: The Hatton Press, new ed., rev. and enl. by R.B. Foster, pp. 253–273, on p. 261.
Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The complete guide to processes, identification & preservation. London, Los Angeles: Thames & Hudson, on p. 17.
Coustet, Ernest (1921): Le cinéma. Paris: Librairie Hachette, on p. 6and on pp. 107-108. (in French)