It was during this period that Riley began to paint the black and white works for which she first became known. They present a great variety of geometric forms that produce sensations of movement or colour. In the early 1960s, her works were said to induce sensation in viewers as varied as seasick and sky diving. From 1961 to 1964, she worked with the contrast of black and white, occasionally introducing tonal scales of grey. Works in this style comprised her first 1962 solo show at Musgrave's Gallery One, as well as numerous subsequent shows. For example, in "Fall", a single perpendiculars curve is repeated to create a field of varying optical frequencies. Visually, these works relate to many concerns of the period: a perceived need for audience participation (this relates them to the Happenings, which were common in this era), challenges to the notion of the mind-body duality which led Aldous Huxley to experiment with hallucinogenic drugs; concerns with a tension between a scientific future which might be very beneficial or might lead to a nuclear war; and fears about the loss of genuine individual experience in a Brave New World. Her paintings since 1961, have been executed by assistants. She meticulously plans her composition's design with preparatory drawings and collage techniques; her assistants paint the final canvases with great precision under her instruction.