the Battle of the Coral Sea and the Battle of Midway, ships painted completely blue came under attack less often than ships wearing two-color schemes. On the advice of United States aviators the blue color was darkened and used extensively in the western and southern Pacific from mid-1942 through 1945 to minimize detection and identification by enemy aircraft. Dark blue also proved effective under artificial illumination during night actions. Upper surfaces of aircraft operating from carrier decks were painted a similar shade of blue. Sailors were ordered to wear dungarees rather than white uniforms when topside. The Thayer system was white with large polygonal patches of light sea blue (called Thayer Blue). This measure was most useful in Arctic latitudes with extended twilight and frequent fog and cloud cover. Purity of color was important for full realization of the Purkinje effect where some colors appear lighter and some appear darker at low levels of illumination. Darkening the pattern increased course deception, but increased visibility at night and in haze. Measure 32 was a medium pattern of obtrusive polygons in navy blue or black, against background polygons of lighter grays and greens. This measure emphasized mistaken identity and course deception to complicate submarine attack. Patterns were carried across the bow, and light gray was used aft to blend with the wake. This measure was based on the World War I dazzle system modified by observations in the western Pacific; and was applied to most surface ships in the Pacific during 1944 and 1945. Different patterns were devised for classes with large numbers of ships so the pattern would not identify the class of ship. Royal Navy Between the world wars, Royal Navy ships were painted dark gray in the Home Fleet, light gray in the Mediterranean and Caribbean Seas, and white in the Indian Ocean and western Pacific. Many Home Fleet ships were painted medium gray during 1939 and 1940 to decrease visibility from the peacetime dark gray. In the first year of the war British captains largely painted their ships as they saw fit. is believed to have been the first ship to adopt a disruptive camouflage paint scheme in December 1939, and several G-class destroyers of her flotilla used a similar scheme of contrasting stone colored polygons. When concern arose about German aerial reconnaissance of Scapa Flow, some Home Fleet ships were painted with disruptive Flotta schemes of dark