As a young American in Paris in 1949 - four years out of the Army and one year out of a Boston art school - Ellsworth Kelly had an epiphany. The key to creative inspiration was in the world around him, not in other artists' studios or at the Louvre. If he paid close attention to, say, the contour of a window, the shape of a leaf, the play of light and shadows on man-made and natural forms, his art would emerge.

"I think if you can turn off the mind and look only with the eyes, ultimately everything becomes abstract," the artist told an interviewer in 1991, reflecting on the evolution of his work. Six years later, he told a reporter: "I'm not searching for something. I just find it. The idea has to come to me . . . something that has the magic of life."

By then, Mr. Kelly, who died Sunday in Spencertown, N.Y., at 92, was internationally known as a master of geometric abstraction, the high priest of crisp, hard-edge shapes and vivid colors. Art history books had classified him as an exemplar of minimalism's cool aesthetic, which gathered force in the 1950s and '60s in reaction to abstract expressionism's emotional aura.

"Minimalism was a necessary, even valuable, phase of modern art," states H.W. Janson's monumental History of Art. "At its most extreme, it reduced art not to an eternal essence but to an arid simplicity. In the hands of a few artists of genius like Kelly, however, it yielded works of unprecedented formal perfection."

But for Mr. Kelly, perfection had little to do with geometry. What he wanted was joy. He found it through a keen perception of things he saw.

Reviewing the Guggenheim Museum's 1996-98 traveling retrospective for the New Yorker, Simon Schama wrote that the strength of Kelly's "opulently colored and gracefully formed" work was "its winning combination of perceptual subtlety and sensuous immediacy: a philosophical delicacy of vision pumped up into raw chromatic heft."

Ellsworth Kelly was born May 31, 1923, in Newburgh, N.Y. The second of three sons, he honed his powers of observation early, developing what would become a lifelong interest in bird-watching. He made his first oil painting in high school and studied art at Pratt Institute in Brooklyn from 1941 to 1943, when he was inducted into the Army. Eventually stationed near Paris, he visited the city but was unable to go to the museums that he would come to know a few years later.

Discharged in the fall of 1945, he studied at the School of the Museum of Fine Arts in Boston under the GI Bill until spring 1948, then returned to Paris with funds from the GI Bill, where he essentially educated himself by embracing the international art community, going to museums and traveling.

Mr. Kelly would become a pillar of 20th century American art, but his six-year sojourn in France launched his career. That's where he painted Plant I, his first use of a white form on a black ground, and produced his first lithographs, collages, reliefs and shaped-wood cutouts. Turning away from figurative work, he joined two painted panels in Window, Museum of Modern Art, Paris. Often cited as a seminal piece, the 1949 construction transforms an architectural detail into a spare, geometric abstraction.

Mr. Kelly returned to the United States in 1954 and settled in New York, where he quickly made connections with artists and dealers. His first U.S. solo exhibition opened in 1956 at Betty Parsons' avant-garde gallery in Manhattan; in 1963, he moved on to other prestigious galleries, including Sidney Janis, Leo Castelli, and Blum-Helman.

In the late 1950s and '60s, he lived and worked at an artists' community on Coenties Slip, a tiny street overlooking the East River, where his neighbors included Robert Indiana, James Rosenquist, Agnes Martin, and Jack Youngerman. He moved to Spencertown in 1970 and established a large studio there. He met his companion, photographer Jack Shear, in 1982.

Mr. Kelly left a huge legacy of parallel but interconnected bodies of work - paintings, sculptures, drawings and prints - made over long periods of time. Throughout his career, he investigated natural forces and biomorphic forms as well as man-made curves and grids. His work has been exhibited at and collected by an international array of museums, and he has made a mark with sculptural commissions in prominent places such as the Tokyo International Forum, Boston's federal courthouse, the Art Institute of Chicago, and Philadelphia's Barnes Foundation.

In a book about the prints, critic Dave Hickey wrote: "Kelly's idea, it would seem, is to impose order on the world without bringing the world to order. As a result, when the knowing skill of long practice begins to refine his way of working, begins to disguise the rowdiness of its roots, Ellsworth Kelly is happy to relinquish control, to make some mistakes, to let some things happen, and then look again - and then maybe adjust things a little here and there, as the eye suggests they should be. Then proceed."