to have been unable to see Broke. Escort captains observing Broke experimented with similar schemes including polygons of dark gray or dark blue for increased disruptive contrast, while others tried painting their ships entirely white to emphasize concealment. The Admiralty omitted light gray from Peter Scott's scheme. White with large polygonal patches of light sea blue and light sea green was adopted in mid-1941 for use exclusively on destroyers and smaller ships engaged in anti-submarine operations. This was an effective scheme under typical North Atlantic weather conditions of fog and overcast. were delivered painted white with a pattern of sea blue and light gray in an American Western Approaches variant. These were colors used in American camouflage measures; but the pattern was unique to ships produced for the Royal Navy and was replaced by Admiralty schemes and colors during refit. The Home Fleet destroyer scheme was similar to the Western Approaches scheme but used darker shades of blue and gray on the rear third of the ship, to assist in station-keeping. British decks were usually dark gray. The Admiralty's informal approach changed when a branch of the Naval Research Laboratory was established at Leamington Spa under Commander James Yunge-Bateman to test ship camouflage schemes experimentally. Painted models were floated in a large tank and examined against different backgrounds, using theater lamps to simulate varying lighting conditions. An experimental coating able to change color was tested on Royal Navy submarines. On suggestion by Professor Leslie Cromby, lead oxide was applied to the hull, enabling it to become black on application of a solution of sulphite and sea water for night operation. For day sailing, a solution of hydrogen peroxide and sea water would be applied, producing sulphate and returning the hull to a white colour desirable for daytime conditions. German Kriegsmarine German Kriegsmarine ships before the Second World War were either light gray overall or had dark gray hulls, and many retained this scheme during the war. The cruiser Deutschland, for instance, had a gray hull and light gray superstructure in 1934. Others had dazzle camouflage, usually in combinations of pale gray, dark gray and sea blue. For example, the hull of the battleship Scharnhorst had a dazzle pattern of stripes on a gray background in 1940, but some of these were later painted out, and the bows forward of the main guns painted black. Scharnhorst was not camouflaged against air