For future reference - a useful link for potential access to primary and secondary research material on colour theory. According to the RCA website it is 'one of the largest and most comprehensive collections of colour-related materials in the world', covering art, science, theory and practice and consisting of books, pamphlets, colour swatches and journals. In the oversize collection, they have a copy of Josef Albers' Interaction of Color, in its original edition from 1963 with full size silk-screen plates.RCA Special Collections is housed in a purpose built archival storage storage facility with a temperature controlled environment, on the top floor of the Library in the Common Room Block of the Royal College of Art, Kensington Gore, London, SW7 2EU. Access is open to all bona fide researchers (I.D. required) by appointment only through email at special-collections@rca.ac.uk or by telephone +44 (0)20 7590 4234. https://www.rca.ac.uk/more/special-collections/special-collections-books/colour-reference-library/Featured image: Digital photograph of my darkroom wall (shadows of drying line with film clips)