between Rockaway Park and Euclid Avenue or Broad Channel, plus some weekday mid-afternoon service provided between Far Rockaway and Euclid Avenue. During the late night-early morning hours, service operating to and from Euclid Avenue on the IND Fulton Street Line in Brooklyn was extended between roughly midnight and 6:00 a.m., which were the hours when the did not run to and from Far Rockaway. At those times, the HH would operate from Euclid Avenue to Rockaway Park, then to Far Rockaway via Hammels Wye, and finally back to Euclid Avenue, thus earning this night owl service the unofficial nickname of Rockaway Round-Robin. Between September 11, 1972, and August 29, 1976, the shuttle's identifier was known as the (colored aqua blue), although during rush hours this train was extended all the way to Jamaica–179th Street on the IND Queens Boulevard Line in Queens. Afterward, the designation (colored green) was used for the shuttle, running to Broad Channel, although during rush hours this train was extended all the way to Bedford Park Boulevard on the IND Concourse Line in the Bronx. In 1979, the MTA released a new coloring scheme for subway routes based on trunk line; CC service was assigned the color blue, because in Manhattan it used the IND Eighth Avenue Line. On May 6, 1985, the shuttle's identifier was changed to H (still colored blue) instead of reverting to HH, as the New York City subway system had abolished two-letter designations by then. Prior to 1993, late night service went to Lefferts Boulevard with no service to Far Rockaway. During this time again, the Rockaway Shuttle ran from Rockaway Park to Far Rockaway, to Euclid Avenue, and finally, back down to Rockaway Park. In 1993, service was changed. All late night service traveled to Far Rockaway and service to Lefferts Boulevard was provided by a shuttle to Euclid Avenue. The Rockaway Park Shuttle, designated S, now ran between Rockaway Park and Broad Channel at all times. Also in 1993, special diamond service began running from Rockaway Park to Manhattan during the morning rush, and from Manhattan to Rockaway Park during the evening rush. Formerly, some maps and trains had shown the current S service in blue. Since May 2004, the official system map shows the Rockaway Park Shuttle as carrying a grey bullet. Recent prints, however, depicted the service itself in blue, but has been changed back to grey,