Coleman was born in Bristol on the 22 November 1916 and went to live in what was formerly Rhodesia with his father soon after. He returned to England at the age of 14 to attend school at Frensham Heights where he cultivated his desire to work in the theatre. He auditioned for the Old Vic Drama School in the mid 1930s, in the presence of Lillian Baylis, and it was here that he was introduced to Tyrone Guthrie. Coleman had embraced the strong pacifist beliefs advocated by his stepmother and the outbreak of war saw him register as a Conscientious Objector. He turned to agricultural work, harvesting fruit but later found an opportunity to flex his acting muscles again when he joined the fledgling Pilgrim Players acting company.
Returning to the Old Vic he worked alongside Eric Crozier who directed him in a production of Androcles and the Lion. Throughout this early part of his career Coleman met and worked with a host of legendary figures from the British stage such as Alec Guiness, Laurence Olivier and Edith Evans but he also developed an interest in direction. This originated when Guthrie asked him to assist in coaching the speaking roles for performers in Britten realization of The Beggar’s Opera. The production was mounted by the recently formed English Opera Group and presented at the Arts Theatre Cambridge in May 1948. Coleman first met Britten (who was acting as répétiteur) and Pears during an early rehearsal.
The collaboration between composer and director continued the following year with an entertainment for young people which comprised a play (Let’s Make an Opera!) about writing an opera and then performing it. Coleman's directorial work on The Little Sweep at Aldeburgh’s Jubilee Hall during the second Aldeburgh Festival of Music and the Arts in June 1949 was highly successful and led to his taking the play/opera on tour. From this time onward he enjoyed numerous visits to Britten and Pears’s home in Aldeburgh where they discussed possible new projects. Coleman went on to direct Billy Budd, the opera composed for the Festival of Britain, and premiered at the Royal Opera House, Covent Garden in December 1951. A significant outcome of the project was the close and enjoyable working partnership that emerged with the artist John Piper. Opera, by this time, had become something of a specialism and Coleman worked on a variety of productions, such as Samson and Delilah and Don Pasquale at Sadler’s Wells. His work on Britten’s coronation opera Gloriana garnered praise amid the famously cool critical response to the work that followed its Gala premiere on the 8 June 1953.
Coleman’s last major collaboration with Britten occurred in September 1954 with the successful English Opera Group (of which he was now an artistic director) production of The Turn of the Screw at the Teatro la Fenice, Venice. He negotiated the technical difficulties and considerable demands that the narrative offered—eight scenes in each of the two acts—with a great deal of skill.
In 1954 Coleman left England to work in Canada in both theatre and in CBC television. He returned to the UK occasionally to take up work which included the direction of television opera for the BBC: first, La Boheme and later, in 1966, Billy Budd (conducted by Charles Mackerras) with a cast comprising Peter Pears (recreating on film the role of Captain Vere), Michael Langdon as Claggart and Peter Glossop as Billy. During the 1970s he worked on BBC drama productions such as Anna Karenina (1977) with Nicola Paget and Eric Porter, and he directed Helen Mirren and Richard Pascoe in As You Like (1978) for the acclaimed BBC Shakespeare series.
Differences in approach to staging television opera prevented Coleman from working on Peter Grimes in 1969 and Owen Wingrave in 1971 when both works were filmed at the Maltings for BBC television, a decision that Britten came to regret as it led to a temporary rift between the two. However, he returned to the Red House and renewed his friendship with Britten well before the composer’s death in 1976. Ever keen to explore new things, Coleman turned to teaching and took an active role in the Britten–Pears School for Advanced Musical Studies (now the Britten–Pears Young Artists Programme), directing and coaching many productions throughout the 1980s and early 90s.