Light and Colour Theories, and their relation to light and colour standardization

by Joseph W. Lovibond

Three units red saddened by one neutral tint, completely describes a colour matched by a red glass standard of four units red, combined with a blue and yellow of one unit each, and is denoted

R. 3·0 + N.T. 1·0

A given red of three units, which is one unit brighter than standards, after having been saddened by one unit each of red, yellow and blue, is matched by three units of red and is correctly described by

Red 3·0 + Light 1·0

Three units of violet, of standard brightness, is matched by a red and a blue glass of three units, and is correctly described by

V. 3·0

Three units of orange, of standard brightness, is matched by a red and a yellow glass of three units, and is correctly described by

O. 3·0

A binary red violet of standard brightness, in which red preponderates by one unit, is matched by four units red, and a blue of three units, and is correctly described by

R. 1·0 + V. 3·0