Suburban coaches were designed for the transportation of large numbers of people over short journeys and were used particularly around London by all four railway companies prior to Nationalisation. There was not the same urgency in replacing old non-corridor stock with new standard carriages, as there had been with main line stock, and reasonable pre-nationalisation designs continued to be built until 1953. The new British Railways standard non-gangwayed stock appeared initially in plain red livery, but later in lined maroon or (on the Southern Region) in plain green. Later they were all painted unlined blue.