When they first appeared nearly 20 years ago, Thomas Downing's paintings -- a few circles on bare canvas; there was next to nothing there -- were shocking.

Their colors were so succulent and their formats so severe that they were stared at with wonder -- until symmetries eroded and stillness became movement and it became apparent this must be The New Art.

That '60s rush is over now. A thousand imitations, and perhaps excessive praise, have worn down the newness of Washington Color Painting. "The Circle Paintings: 1960-1979," the small Downing retrospective at the Osuna Gallery, 2121 P St. NW, is a show that fills us now with affectionate nostalgia. After seven years away -- in Houston and Manhattan and, of late, in Provincetown -- Tom Downing has come home.

His influence was huge, once. In the last years of the '60s, his students at the Corcoran took Downing as a challenge, and an inspiration. Morris Louis was already dead, Kenneth Noland had moved elsewhere, Gene Davis was sui generis and Howard Mehring was a recluse; but Downing, who had known them all -- had studied with Noland and shared a studio with Mehring -- was passionately there.

His finest pictures were thrilling. Subtle and yet raw, luxurious yet simple, his "dials," "grids" and "rings" were derisively labeled "Polka Dots," but they were indeed his finest.

It took a while to see them, and it takes a while still. His show is best seen slowly. His rings at first seem "empty," his grids too simple; but spend a while staring at his "Pepper" (1961) -- watch for the blue square -- or look at "Red Times Blue" (1964) until its colors spin.

In June he will be 50. He once seemed a pioneer, a young man from Virginia who had studied in Manhattan (Seeing the Gorkys, Pollocks and de Koonings there), and he had gone to Paris to study with Leger. When color painting blossomed, Downing understood what was going on.

His art, despite its purity, had risen out of gesture. His first circles were made freely with one stroke of the loaded, sometimes-splattering brush. He acknowledged in his pictures not just Jackson Pollock, but Newman, Albers, Noland, and Morris Louis.

Still seduced, in those days, by the thought that painting was a progression, we expected Downing, Mehring and Noland to provide triumph after triumph. None succeeded. Mehring's art went stale; Noland seemed to flounder. Downing, of the three, became the most constant. He kept on painting circles, sometimes overlapping them and adjusting their proportions, movements and colors -- and the colors of their grounds. His art did not progress. Of his picture here, the finest are the earliest. The newer works, in contrast, seem perhaps too fine-tuned.

His sort of color painting today is not in fashion, but Downing sees the sea from his house in Massachusetts and is in no hurry."I have a very long road ahead of me," he says. "In five years I'll begin to show up again." His greatest contribution may well be behind him, but his paintings will survive. The show closes April 7.

Robyn Jonson Ross, in her exhibition at the W.P.A., 1227 G St. NW, does not seem to be one artist, but two, or perhaps three.

There is Ross whose strong ink drawings of birds, fish and beasts are wonderfully penned and both frightening and funny. There is another Ross who makes richly textured pencil drawings of big flowers. And then there is the Ross who -- perhaps influenced by Frank Stella, Enid Sanford or Ron Davis -- makes colored abstract pictures, on canvas and on plexiglass, that fall flat in contrast to the other two Rosses.

Her drawings, done in pen or ink, are full of energy and passion. It takes many years to learn to draw this well. Her paintings, insecure and raw, seem the work of a beginner. The exhibit closes on March 22.

There is something feminine -- and intentionally feminist -- about the drawings and the fetishes made by Constance Costigan, now at Barbara Fiedler's, 1621 21st St. NW. Her drawings, done subtely with graphite, show beaches, boulders and hills, which seem about to become flesh, knees, breasts and hips. Her fetishes -- "Numia," she calls them -- are made of feathers, sticks and bones. Most of them are delicate. Were a witch to wave them in some ancient rite, they would fly apart. Other "Numia" resemble wombs.

Costigan, who teaches at George Washington University, is never sloppy in her work. One leaves her show impressed by the care and patience she has poured into her art. It closes March 23.

The Jack Rasmussen Gallery, 313 G St. NW, is showing paintings, sculptures and collages by Philadelphia's Harold Jacobs. It is a schizophrenic show. His sculptures -- piles of guitar and banjo cases he has daubed with paint, or a two-part work composed of inflated inner tubes from large tractor tires -- have about them a dreary stage-set thinness. His large paintings -- they seem to be inspired by his work with black inner tubes, although it may be the other way around -- are ominous and playful, but his small collages are so much finer than his other works that they steal the show. Made of many things -- wooden matches, thread, shells, sandpaper, and fur -- they are well-put-together objects with elegance and verve. Perhaps Jacobs is a miniaturist. When he attempts to work at the scale of the stage, his art seems hollow, pale and strained. His show runs through March. Charlotte Robinson has taken a giant step forward in her new paintings at Gallery 4, 115 South Columbus St., Alexandria. Entitled "Interior Landscapes," this cycle consists of several large abstract works in diptych and triptych, all of which look out into an inventive landscape which the artist seems to have just discovered within her own imagination. The paintings are filled with a spirit of revelation.

Most successful are the paintings in dark, lush earth tones with almost suede-like surfaces, all very moody and sometimes ominous. The brush-stroking, as well as the imagery, are far more assured than every before. Less resolved, and seemingly too hastily done, are the paintings in pastel tones, which lack the same intensity.

Also on view are several recent prints, some based on earlier works -- including Robinson's drawings taking off on the pomposities of various critics -- and some in fine new silkscreens, most notably "White Nile," "Blue Nile" and "Crossroads III". The show closes today.