Coles spent his early career playing with R&B groups, including those of Eddie Vinson (1948–1951), Bull Moose Jackson (1952), and Earl Bostic(1955–1956). He was with James Moody from 1956 to 1958, and played with Gil Evans‘s orchestra between 1958 and 1964, including for the album Out of the Cool. After this he spent time with Charles Mingus in his sextet which also included Eric Dolphy, Clifford Jordan, Jaki Byard, and Dannie Richmond. Following this he played with Herbie Hancock (1968–1969), Ray Charles (1969–1971), Duke Ellington (1971–1974), Art Blakey (1976), Dameronia, Mingus Dynasty, and the Count Basie Orchestra under the direction of Thad Jones (1985–1986).
In 1985 Coles settled in the San Francisco Bay area; he recorded with Frank Morgan and Chico Freeman the following year. After his return to Philadelphia in 1989 he again worked with Morgan and was part of Gene Harris‘s Philip Morris Superband. In 1990 he recorded with Charles Earland and Buck Hill. Coles recorded as a leader several times over the course of his career. He died of cancer on December 21, 1997 in Philadelphia.