Part of a Pullman porter's job was to make up the sleeping berths in his assigned sleeping car, and to provide extra blankets to passengers requesting them. The standard Pullman blanket in the 20th century was dyed a salmon color, which became almost a trademark of the company. When a blanket became worn or damaged in service, it was assigned to those blankets reserved for porters' use.
This wool blanket in use between the 1930s and the 1950s, was used by African American railroad porters. According to Pullman service rules, a porter's blanket was never to be given to a passenger. Ostensibly to avoid mixing these with the passengers' blankets, the porters' blankets were dyed blue. This was to comply with statutes in the South that dealt with the segregation of blacks and whites. The Pullman service rules were applied nationwide throughout the Pullman system, not just in the South. Dyeing the blanket blue made it easy to tell which blankets were used by passengers and which blankets were used by the African American porters and attendants. A dyed-blue Pullman blanket is today extremely rare, given its negative racial symbolism.