Just being a famous artist these days can be exhausting. You could see it in the ashen face and darkly circled eyes of Israeli-born Yaacov Agam, 53, as the opening night crowd of Agam fans -- including chief of protocol Leonore Annenberg -- pressed in around him, begging autographs. Time after time, like a magician, Agam produced a fistful of colored pens from the darkness of his dinner jacket to scrawl a rainbow across the blank pages of catalogs and expensive books by and about the artist. "Art is a rainbow!" he exulted, before sinking again into the vortex of the crowd.

The occasion was the opening on Wednesday of Agam's first Washington show in five years, a black-tie evening at the Art Fair gallery in Friendship Heights. It climaxed with the reading of a proclamation from Mayor Marion Barry declaring June 4th "Agam Day," and calling Agam "the greatest artist of our generation." The artist bowed of thank-you with his stocky, five-foot frame, and glanced defensively -- much like a puppy about to be kicked -- at a critic standing nearby. "Do you think you're the greatest artist of our generation?" the critic whispered in his ear. "I am a bubble," he replied, "and if I don't get some air I shall collapse."

Yaacov Agam's American image has changed dramatically since a major retrospective last fall at the Guggenheim Museum, and -- as he puts it -- "sine the Reagans." Through Leonore and Walter Annenberg, who own 18 of his works, Agam was introduced to President and Mrs. Reagan at Blair House last January, just before the inauguration, and now there are four Agams in the White House. Until then, Reagan had been known here chiefly for his interest in cowboy art.

And in Washington, Agam had been known chiefly for his big, colorful relief painting at the Hirshhorn, called "Transparent Rhythms "II," a characteristic work in which the abstract patterns constantly change as the viewer walks by. It is still typical of all 18 types of graphic art he has since devised, and which he calls, variously, Agamographs, Multigraphs, Dynamographs, Polymorphs, Interspaceographs, and -- for viewing them all -- the new "Agamoscope," a pair of eyepieces with prisms that are $400 a pair in the signed, numbered edition, and $80 in the unsighed edition. Agam makes editions of everything, often in three sizes: small, medium and large, all correspondingly priced.

But in the '70s, Agam was already famous in Europe. The late French president Georges Pompidu had commissioned him to design an entire room in the presidential Palais de Elysee, a room now removed to the Pompidou Art Center. And along with major exhibitions in world capitals, he designed "the largest stamp ever produced in Europe," a 4-franc issue four times normal size, which he says was printed in 99 colors -- more than any other.

"Nancy had seen his work often at my home in Palm Springs, and liked it," explains Leonore Annenberg, who first "discovered" the artist -- whom she calls "a genius" -- at the opening of the Desert Museum in Palm Springs, of which she was president. After meeting the Reagans, Agam presented them with a bronze cast of his "Peace Star," an 11-pointed, three-dimensional "starbust" from that merges the five-pointed star of Islam with the six-pointed star of Israel. "And, for Reagan, it means even more, because it is also the American star and the Russian star," says Agam. m

"I gave it to the president because he's trying to make peace in Lebanon, and if he does this, it will be a tremendous achievement," says Agam, who like many Israeli artists, deals often, usually symbolically, with the subject of peace. "Peace Star" was originally created, at Menachem Begin's request, to commemorate the Camp David Accords. and both Begin and Anwar Sadat have also been given castings. "I've met a lot of presidents," says Agam, "But never one who was so balanced between the emotional and the rational. He is the only artist who was become a president, and you can feel it. I also gave him another sculpture 'Beating Heart,' because he feels so deeply for the American people."

"The Reagan keep it upstairs on a table, and play with it all the time," said Leonore Annenberg. The sculpture consists of five concentric hearts that move when touched.

"This guy is going to create something that will change the world," says chief fan Marty Blinder, the West Coast publisher who produces many Agam "limited-edition" graphics, an Agam-designed upholstered cube that pops open and becomes a chair, and now the Agamoscope.

If Agam doesn't change the world, he has certainly changed his world. Before the opening -- just in from New York, where he was just in from Paris -- the beaded artist, down-played in a blue silk suit, striped shirt and dark tie, talked animatedly in his hotel suite while his eyes rolled backward and his eyelids hung low, begging for sleep. "I leave Paris at 11 a.m. and arrive in New York two hours earlier at 9 a.m.," he marveled of his Concorde trip.

The seventh child of a poor cabalistic Israeli rabbi, Agam studied art at the Bezalel art school and was sent by one of his teachers to study in Switzerland in 1951. From there, he went to Paris, married a young Israeli woman from a village near his own, and the two of them "literally starved, and had to go to the Salvation Army for food." In 1953, he had his first one-man show, and sold his first painting to the famous surrealist artist Max Ernst. From then on, he was able to raise three children along with his standard of living. The big leap out of oblivion came after he won first prize at the 1963 Sao Paulo Bienal with his op-like, eye-dazzling work -- the first such prize ever given an Israeli artist. His success since then has not lacked the enthusiastic support of Israel and its supporters. A retrospective at the Museum of Modern Art, Paris, in 1972, clinched his reputation. He still believes in magic, and no wonder.

Keeping himself awake with his own excitement, Again pulled an array of visual aids out of his chic leather bag of tricks -- collected evidence of the importance of what he was doing: an inscribed photo from Ronald Reagan, a Xerox of a thank-you letter from Mrs. Jehan Sadat, a first-day cover with his 4-franc stamp. But most important to Agam at the moment, "much more important than art," he said, were several fat volumes constituting a visual literacy project he has designed for young children, and which, he says, "will expand intellectual and creative capacity beyond anything man has ever known, by helping children to develop the right lobe of the brain." The program is already getting under way in Venezuela and France, and according to Agam, may also be piloted in America soon. He pulled out a letter from the Dwight School in New York as evidence.

The buzzer on his watch sounded. But Agam continued answering the question of whether he had become too commercial, a one-man industry of sorts, with too many editions, books and other high visibility projects. "What do you want me to do, shut off my brain?" he asked. "I think of these things -- like my new camera that sees two separate images, or my shoes that feel like you're walking on air, and I find someone to make them. I can't do it. I'm an artist, not a shoe-maker. I told Stanley Marcus [of Neiman-Marcus] about it. He's getting somebody." Politics, peace or shoe leather, Agam deals at the top.