Photochromy is the art or process of reproducing colors by photography.Webster's Revised Unabridged Dictionary (1913), edited by Noah Porter[Note] Photochromy is not to be confused with photochromism (photochromics), a reversible color change induced by light energy (previously termed "phototropy").The Focal Encyclopedia of Photography, page 1079, Desk Edition (1969), Focal Press, Furthermore, a so-called photochrom–a black-and-white photograph colored by hand using an 1880s method–is not the result of the photochromy process (although the more specific and later 1890s method of Lippmann color photography to create what was sometimes termed a "direct photochrome" or "Lippmann photochrome" is such a result).
History Colored images by direct exposure from nature using a Lippmann plate
Color printing method by the bleach-out process. See Utocolor and Cibachrome
See also Color photography
Notes In the original publication in 1891, Lippmann reports on photochromy in which he describes his famous method of photography in colors, the so-called "interference" method, based on the action of stationary waves.
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