Richmond’s shift throughout the 1970s from the chthonic ‘spirit in the mass’ of his Ronda work to what became a nearly pyrotechnic colourism was not, however, straightforward.

By the late 1960s, Richmond had painted a large, confident body of work, but he was still reluctant to exhibit in London, mostly because he believed his paintings to still be too similar to Bomberg’s.

But around 1969, he completely changed his mind about this and, in fact, how he saw his work, when he met Harry Thubron. An artist and formative art educator, Thubron inspired by the Bauhaus and Herbert Read, encouraged his students to develop not only their technique, but also their visual literacy.

The two men became close friends despite their widely differing opinions of Bomberg and Picasso (which often made for explosive discussions), they nevertheless had a solid friendship. And Thubron had a decisive effect on Richmond’s work when he reintroduced him to the possibilities of colour theory.

Selection of colour exercises from Richmond’s sketchbooks (c. 1969-1971)

Fed up with wondering what would remain of his work if it were stripped of Bomberg’s influence, Richmond decided to exorcise this influence. He had always based his work on line and form and now wanted to intuit colour, so he stopped drawing and painting almost entirely and instead made colour exercises.

Following the example of Johannes Itten, Paul Klee and other Bauhaus masters, he filled notebooks with abstract, largely geometric diagrams to illustrate various contrasts of colour saturation, extension, complements and value.