Kelly made a number of two-panel paintings combining curved and angular shapes. He was interested in the effect of combining stable, straight-edged forms with dynamic, curved forms. These diptychs demonstrate Kelly’s long-standing interest in presenting shape and colour as ‘figure’ against the ‘ground’ of the wall. Orange Relief with Green belongs to a series of reliefs, where the forms appear to press into or penetrate one another. Here, the orange panel is superimposed onto the green panel.