Artist in oil, pastel and pencil, notable for portraits, mainly of children. She was born in Cairo, Egypt, and studied at the Westminster School of Art before World War II with John Farleigh, Bernard Meninsky and Mark Gertler. Between 1940–5 served in the Women’s Auxiliary Air Force in the United Kingdom and the Middle East. After hostilities, she worked in Egypt for the Egypt Exploration Society and for the Jordanian government before returning to London, after which she freelanced. She said that pastelists such as Chardin, Degas, La Tour and Angelica Kaufmann and the draughtsmen Augustus John, Rubens and Ingres were influences. Colles was a member of PS, also exhibiting at RP and RA. In 1962 she had a solo show at Leighton House. She wrote Portraying Children, 1953, and in 1971 published Christian Symbols Ancient & Modern with Heather Child, the artist and calligrapher, who was a lifelong companion.