Artist Sam Gilliam's signature strokes on draped cloths, towering panels and traditional canvases are part of our everyday lives, on display in museums as well as at libraries, banks and Reagan National Airport. For almost 50 years, Gilliam has been an ever-changing force in Washington's arts circles, even as his work and recognition have grown far beyond the city.

In 1967, Gilliam received his first solo show at the Phillips Collection, where he was saluted as an innovator in Washington's Color School, a movement in the '60s and '70s that produced bursts of color in geometric forms and fanciful shapes.

Gilliam's work is included in the collections of the Metropolitan Museum of Art, the Museum of Modern Art, the Tate Gallery in London and the Moderne in Paris. The Corcoran Gallery of Art mounted a retrospective of his career in 2005.

This week, Gilliam, 77, returns to the Phillips, where as part of its 90th anniversary, he was asked to make a work to complement its elliptical stairway. The panels he created, between 10-and 8-feet-long, are suspended on wire in a 24-by-24-foot well. They radiate with delicate and intense bursts of color. Some of the banners have cutouts of empty frames so views of each bold explosion are not blocked.

Dressed in jeans and a gray sweater, Gilliam, 77, talked about his inspiration as a crew hung the long panels.

"I'm calling the work 'Flour Mill.' I started thinking of the approach by studying one of the early abstract paintings I first saw here in Washington. Arthur Dove and his 'Flower Mill II' inspired the painting. Let's see that's 1938. He used landscape as a way of connecting with painting. There's also a real connection to Mondrian. The green relates to landscapes. Some of the areas connect more to water. That's something I wouldn't have said in the 1960s.

"I didn't look at the staircase and the space. I didn't want to worry about it. These panels are 10-feet tall. The material is nylon, and I used an acrylic paint. The acrylic has a wetting agent that stains the nylon, so the plastic on the table has the same pattern.

"In the studio I hung them on a rod away from the wall. Now I have to arrange it to make it into a work. Now I'm going back to the studio because I think I need more, maybe two more panels. The next one is bronze and green because it needs some accents.

"The painting never closes in that sense."

The installation will be on view until April 24.