Facing colour engineers and support corps normally had a single branch colour, although exceptionally each regiment of Swedish artillery had its own facing colour until 1910. The United States regular army after the American Civil War adopted a universal dark and light blue uniform under which each regiment was distinguished only by numbers and other insignia, plus branch colors. The latter were yellow for Cavalry, red for Artillery and white (later light blue) for infantry. Combinations of colors such as scarlet piped with white for Engineers, orange piped with white for the Signal Corps and black piped with scarlet for Ordnance personnel
George Palmer (colour theorist) is moved by its own ray." This statement has proved true in regard to the number of different light sensor types, the cones, in the human eye, if not in regard to the claim of three kinds of light. Twenty-five years later a similar statement was made by the eminent physicist Thomas Young. Voigt, in his report on Giros von Gentilly, describes him as having stated that colour blindness arises if one or two of the three kinds of "particles" (light sensors) in the retina are inactive, a statement found to be accurate. In 1786 Palmer provided a hypothesis for