In 1951, he had his first one-man exhibition at the Galerie Arnaud in Paris featuring many of his collages, reliefs and drawings. It was at this time that he met such influential figures as Eduardo Paolozzi and Jean Arp. After his first one-man show in the United States in 1956, he met Richard Kelly, the lighting designer and consequently received commissions to execute lobby and restaurant sculptures in the new Transportation Building for Penn Centre in Philadelphia. By now his reputation was confirmed.
By 1959, he had enjoyed considerable success in a number of exhibitions and produced his first floor pieces for a show at the Betty Parsons Gallery including 'Gate' and 'Pony'. In this year, art historian Jules Langsner termed the current of American geometric abstraction "Hard-edge painting" connoting the shaped panels of bright color and rigid form created by Ellsworth Kelly and his contemporaries. Ellsworth Kelly moved out of Manhattan in 1970 and set up a studio in Chatham and a home in nearby Spencertown, New York; he lived and worked there until his death in 2015.
In his painting and sculpture, Ellsworth Kelly liked to explore the complexities that a simple design could offer up. He favored smooth flat surfaces with hardly any surface texture. He abstracts the forms from observations of the real world, such as shadows cast by trees or the spaces between architectural elements. He was greatly inspired by Picasso's outline painting, 'The Kitchen' and this informed his abstractions and reliefs for much of his career.
Ellsworth Kelly frequently felt frustrated with the way his work was received. He felt that he was ahead of his time, and that with the acclaim being heaped upon the American Expressionists he was not getting his due. His many works in the Hard Edge style, however, have been influential and his work is regularly featured in exhibitions.
"The form of my painting is the content. My work is made of single or multiple panels: rectangle, curved or square. I am less interested in marks on the panels than the "presence" of the panels themselves. In "Red, Yellow, Blue," the square panels present color. It was made to exist forever in the present; it is an idea and can be repeated anytime in the future."