Colman had been an employee of James Tegg, and subsequently took over Tegg's business on the latter's retirement; he advertised his purchase of Tegg's "entire Stock-in-trade" in The Colonial Literary Journal of 1 August 1844. In this advertisement, Colman alluded to "an experience gained in one of the first wholesale houses in London" - this was likely to have been with Thomas Tegg, father of Colman's colonial employer. Aside from this, Colman's background is largely unknown. It seems unlikely that he was any relation of the various nineteenth century American publishers by the name of Colman (which included a bookseller and art dealer, William A. Colman, in New York), since his business dealings, even after he set up his own business, were principally with the Tegg family.
In various advertisements, Colman described himself as a bookseller, publisher, stationer and bookbinder. By February 1848, Colman had formed a partnership with William Piddington, trading as Colman and Piddington, though Colman himself actually departed Sydney on the St. George bound for London on 1 March 1848, possibly for reasons of ill health. He died at sea, aged 35 (Sydney Morning Herald 10 October 1848).
