Middleton was born in 1910 in Belfast. He attended the Belfast College of Art as a part time student, attending evening and Saturday morning classes.

Middleton saw paintings by Van Gogh at the Leicester Galleries in 1928 and in 1931 he went to Belgium with his father and was impressed by the Flemish masters as well as by the symbolist painter James Ensor. The accomplished draughtsman and the expressionist, the conflicting sides of Middleton’s artistic persona that were to provide the dynamic of his career, are already in evidence. Some time later, in the 1930s, Middleton seems to have been introduced to the work of Salvador Dali, whose influence was to be profound. Surrealism seems to have acted as a liberating force for Middleton, allowing his imagination full rein and also providing a way in which disparate elements of his life and imagination could be brought together.

Middleton’s early paintings are impressive and fascinating and they seem to be the work of a painter of great talent trying to find his own voice as an artist. In 1939, with the outbreak of war and the death of his wife, Middleton’s work seems to have taken on a new intensity. An intimate knowledge of the back streets of Belfast and a genuine empathy with those who live there is evident in the group of impressionistic paintings worked on during the first part of the war. The broken brushwork and subtle use of color brings a deep poignancy to these scenes, with the emotional power of his works reflecting his own state of mind at this time and the effect of war and the blitz upon his home city.

The early years of the 1940s and the immediate post-war years saw surrealist work of remarkable quality from Middleton. There is no single manner that dominates Middleton’s surrealist paintings, but there are hallmarks that run through much of this work. The frequent use of the female nude is typical of European surrealism and the use of the bird as a symbol throughout his career recalls one of his heroes, Max Ernst, but Middleton’s surrealism is not as derivative or irrelevant as is often suggested.

In 1947 the Middletons settled in Ardglass in County Down, an area of great natural beauty and historic interest, and over the next few years Colin Middleton seems to have drawn great inspiration from the landscape around him. The years when he lived in Ardglass could be considered the time when he became predominantly a painter of landscapes. At times these paintings achieve an intense and almost visionary sense of union with the landscape, evoking its power, its rhythmic energy and its colors.

In the second half of the 1950s there seems to have been a slow but significant change in Colin Middleton’s work and his landscapes become increasingly abstract into the mid 1960s. Certain key shapes and motifs seem to recur and gradually become synonymous with a particular place.