Why is the ninth month called September?
1620s, from French coloration (16c.), from Late Latin colorationem (nominative coloratio) "act or fact of coloring," noun of action from past participle stem of Latin colorare "to color, to get tanned," from color (see color (n.)).
in biology, the general appearance of an organism as determined by the quality and quantity of light that is reflected or emitted from its surfaces. Coloration depends upon several factors: the colour and distribution of the organism's biochromes (pigments), particularly the relative location of differently coloured areas; the shape, posture, position, and movement of the organism; and the quality and quantity of light striking the organism. The perceived coloration depends also on the visual capabilities of the viewer. Coloration is a dynamic and complex characteristic and must be clearly distinguished from the concept of "colour," which refers only to the spectral qualities of emitted or reflected light.