After having studied painting at the Académie Julian in Paris and theatre design in Melbourne, he settled in London in 1956.

By breaking away from the traditional use of "flat wings" scenery, in designing for the theatre he expanded on the revolutionary ideas of the Russian Constructivists and the Italian Futurists in the early part of the 20th century.

His photo essay As a Woman, published in 1976, is an extensive portrait of the unique transvestite and transsexual community of Sydney, Australia.

Live Performance Australia, the premiere body for Australia's live entertainment and performing arts, posthumously selected Kay as one of eighty theatre artists awarded a place in its newly established virtual Hall of Fame.

Launched on 30 November 2007, Live Performance pays tribute to a collection of people on the occasion of its 90th anniversary.