Gray studied painting and design at Goldsmiths College School of Art, London University, where he was a fellow student and friend of the artist-designer Graham Sutherland.
By this time multidisciplinary design consultancies had begun to emerge in the United States.
One of the cofounders of the latter, Misha Black, joined with Gray and Herbert Read to establish the Design Research Unit (DRU) in 1943, a consultancy which sought to provide design expertise for post-war industry, commerce, and the state.
One of his most ambitious projects was the framing, in 1964, of the British Railways corporate identity programme, the working party for which he had chaired.
He was awarded CBE in the 1963 Birthday Honours, and in the same year was elected as Master of the Art Workers' Guild.