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
Colour cast Improper timing or imbalanced chemical mixtures can cause unwanted casts. Colour casts can also occur in old photographs due to fading of dyes, particularly under the action of ultra violet light. These may be correctable on a scanned version of the photograph with image editing techniques. Most digital cameras try to automatically detect and compensate colour cast and usually have a selection of manually set white balance settings to choose from. Otherwise, photo editing programs, such as Photoshop, often have built in colour correction facilities. For film, blue filters and amber filters are used to counter casts. Amber filters are