Over her forty-year career photographer Sally Mann (b. 1951) has become synonymous with black-and white large format photography and nineteenth-century processes, used to depict her family, their environment, and the landscapes of the southern U.S.A. Yet Mann has worked with a variety of processes including colour. This thesis focuses on the printed Cibachromes and unprinted colour transparencies, taken between 1990 and 1994, that make up Mann’s Family Color collection, part of Family Pictures series, the well-known black-and-white photographs of her three children. It outlines work done in situ in the artist’s archive, the consequent discovery of a number of unprinted colour transparencies, and their integration into Mann’s studio through digitization and organization of the collection. An exploration of the production and exhibition history of Family Color is followed by a close-reading of a selection of printed colour photographs from the series, as well as the newly discovered, unprinted images. These comparisons enable the series to be situated within Mann’s larger practice opening up areas for future research.