Singer-actress Mary Martin, actress Claudette Colbert, singer-actor Harry Belafonte, ballerina Alexandra Danilova and composer William Schuman were announced Monday as the recipients of the 1989 Kennedy Center Honors. The honors--in recognition of contributions to the cultural life of the nation--will be bestowed Dec. 2 at a John F. Kennedy for the Performing Arts board of trustees dinner in Washington. President and Mrs. Bush will greet the honorees the next evening at the White House, before a performance-tribute at the Kennedy Center. That gala will be taped for later airing on CBS, and produced for the 12th year by Nick Vanoff and George Stevens Jr. The two-hour special will be sponsored for the seventh year by General Motors. Funds raised from the Kennedy Center Honors Gala support the center's arts education and public-service programming.