As follows is a table of Branch Distinction colors found on officer shoulder boards and cuffs of Royal Navy uniforms per 1918 regulations, Merchant Navy livery as standardized by the British Board of Trade in 1918, U.S. Navy officer uniforms per 1919 U.S.N. uniform regulations, U.S. Army Transport Service regulations in effect from 1933-44, and United States Lines Steamship Co. rate detail from a 1937 passenger list brochure.
References
United States Lines SS Co. SS Washington Passenger List (Westbound) June 1937. United States Lines, New York, 1937
Although not fully detailed in the United States Lines chart, epaulets – or shoulder boards – followed the same design. Of interest is the fact that USL shoulder boards did not use the same button as the uniform coat.