English

Noun

1. A photograph representing an object in its natural colours

A heliochrome, derived from the roots "helios" = sun and "chroma" = color, (literally sun colors), is a color photograph, particularly one developed using the incomplete color processes from the late 1800s and early 1900s.

In the 1860s, John Herschel discovered that a sheet of blackened silver chloride paper, exposed to the sun under red glass would turn red in color. Under blue glass, it turned blue. Other colors resulted in a muddy purple tone.