Photochromy is the art or process of reproducing colors by photography.[1] [Note] Not to be confused with Photochromism (a reversible color change induced by light energy[2]). See Photochromism. Furthermore, a Photochrom is not the result of the photochromy process.
Colored images by direct exposure from nature using a Lippmann plate[3]
Color printing method by the bleach-out process.[4]
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.[3]