Colbourne was born in Ultimo, New South Wales, as the eleventh of fourteen children born to Mary Ann and Richard Colbourne. His parents were Irish Catholic immigrants. He was educated at St Benedict's Convent School in Chippendale.
Career
Colbourne worked as a and was also a stand-up comedian in travelling shows. He married a fellow performer, violinist Hyacinthe Burgess, in April 1936, and had three children. Colbourne followed his father into the ALP and in the 1920s became the secretary of the Petersham branch. He regularly served as a delegate to state and federal conferences.
1930s
During the party split of 1931, the ALP Federal Executive expelled the New South Wales branch of the party, dominated by Jack Lang. Colbourne remained loyal to the Federal Executive and was appointed secretary of a new state branch, known as "Federal Labor". The Lang Labor faction was by far the most successful electorally and in February 1936 the two reconciled. Lang had promised to allow Colbourne to work as a paid organiser for the party, but reneged.
1940s
Colbourne worked as a life insurance agent after losing his ALP position. He established the Industrial Life Assurance Agents' Union, and served as its first federal secretary from 1940 to 1951. He also served on the Leichhardt Municipal Council as an ALP alderman, and was elected to the ALP state executive in 1946.
1950s
In the early 1950s, Colbourne held senior positions with the Federated Ironworkers' Association of Australia and Federated Clerks' Union of Australia. He sided with the "Groupers" in the lead-up to the party split of 1955, and in 1952 was elected state president of the party when his faction won control. In 1954, he was appointed state secretary. When the party split the following year, Colbourne and the New South Wales delegation boycotted the federal conference, but unlike in Victoria remained loyal to the ALP.
1960s
In the 1960s, Colbourne worked in partnership with state president Charlie Oliver. He was elected federal president of the ALP in July 1961, serving a single one-year term and then becoming senior vice-president until 1971. He retired as state secretary in 1969, having served a record term.
