To Richmond, angels were quite literally messengers that heralded flashpoints, those moments when he felt he had truly grasped his subject.

Around 1970, he began to develop an intensely chromatic style, which, like his earlier work, was based on Bomberg’s dialectic ‘immaterialism’. However, he now combined this with his sincere amateur interest in the sciences, particularly physics. While his understanding of science remained personal, even idiosyncratic, he understood that while form can stand alone, colour cannot. So, in depicting the material world, he now used colour as if it were a psychological property, something that could add form to what he believed lay beyond mere physical perception