The first thing Barbara Bush gave to decorator Mark Hampton as they surveyed the dark green walls of George Bush's private office in the White House early last year was a policy statement. "She said, 'The President will never be happy working in a room with walls that are almost black,' " Hampton recalls. Knowing the First Lady "loves light colors," he says, "I suggested white. She said, 'No, too cold," but agreed the room should be something light." With that guidance, Hampton set off for the treasure-stocked warehouse in nearby Virginia where the furnishings of past Presidents await their recall to glory. He selected brown-striped chintz curtains and valences from the Nixon era, three antique mahogany chairs made in 1817 for President James Monroe, and an Oriental rug of yellows, greens and blues, which. Hampton says, "led us to paint the walls a pale, faded green."

Expressing the desires of celebrity clients with his own innate good taste is the debonair decorator's forte. As one of the most sought-after talents in the business, Hampton, 49, is used to going tête-à-tête with those who want the best, regardless of cost. And Hampton obliges; he does not flinch at a $25,000 paint job and quivers only slightly at a $200,000 antique couch. Yet, with a clientele that includes socialites Anne Bass and Nan Kempner. 60 Minutest Mike Wallace and Estée Lauder, the house he most relishes redecorating is at 1600 Pennsylvania Avenue.

"Both the President and Mrs. Bush are people I'm always dying to see," says Hampton, who since 1981 has worked on the Bushes" vice-presidential home in Washington, D.C., and their sprawling summer home in Kennebunkport, Maine. Now with the Bushes comfortably ensconced in the White House, Hampton is on call again—refurbishing rooms in their private quarters as well as the living room at Camp David, and even taking care of such details as the recovering of pillows. On his bimonthly trips to the capital, Hampton may discuss fabric samples with Barbara or make forays into the warehouse. "The idea of buying furniture is practically nonexistent," he says.

While he only charges the Bushes for materials and labor, nonpresidential clients have to pay the full rate—he'd budget $200,000 to $300,000 for starters. In exchange, the decorator and the 16 employees in his midtown Manhattan office provide lavish service. Devotees, such as Kempner, swear he's worth every, uh, hundred thousand. "If I just mention to him in passing at a party that one of my paintings isn't hanging right," says Kempner, "he's over at my house the next morning with a hammer and nails."

That's just part of his lanky, Midwestern charm. "I've rarely met anyone who can be as enthusiastic about a place, a meal, a dress, a chair, or as enthusiastic about people," says designer Bill Blass, a longtime friend. An avid watercolorist, Hampton acknowledges the birthdays of friends with hand-painted cards. For a larger public, he has written a book. Mark Hampton on Decorating, and is working on a second for Doubleday editor Jacqueline Onassis. Two years ago he launched his own line of 18th-and 19th-century-style furniture. Since 1984, he has been a regular on the International Best-Dressed List.

All of which is pretty high-falutin' for a small town farmer's son. Born to a Quaker family in Plainfield, Ind., Hampton was raised to be hardworking ("In my house, a child sitting around was a child who needed to be given a list of things to do") and God-fearing ("I didn't miss a day of church or Sunday School until I was 14 years old"). Attentive as he was to familial duties, his delight lay elsewhere. "Some kids knew all about baseball or cowboys," recalls Hampton. "By the time I was 12, I knew all about Billy Baldwin and Frank Lloyd Wright."

After attending DePauw, a Methodist university, and spending his junior year, 1961, in England, studying at the London School of Economics, Hampton veered from his conservative roots and signed on for a four-month stint with an English decorator, David Hicks. That same year, while traveling in Italy, Hampton stumbled upon Duane Flegel, a Mount Holyoke student, in an American Express office in Florence. Remembers Duane, now 47: "We met abroad, had dinner twice, then went our own merry ways." At first, Hampton's way led him to the University of Michigan's law school. "My parents thought that being a decorator was idiotic, but after a year I faced the fact that it was also idiotic for me to go to law school." He moved to New York, earned a masters in Art History at New York University, and married Duane in 1964, after her graduation. In 1976, after eight years working for Manhattan decorating firms, he started his own company.

Hampton's decorating style took time to evolve, reflecting changes in his life-style. "Our first decorated apartment," Hampton recalls, "was stark and modern-looking, with black and silver walls and geometric carpets." His shift away from that look had little to do with esthetics: "There was no room for clutter." To say nothing of a baby. With the birth of Kate in 1968, followed by Alexa three years later, the accumulation of stuff stirred in Hampton a growing appreciation of the comfortable cluttered style for which he is now known.

Not that just any old clutter makes for home, sweet home. "I'm always straightening pictures, moving things around," says Mark, "and I do the same things to my clients." And his wife, laughs Duane, who owns an antique shop and contributes to the decorating of their seven-room Park Avenue apartment and nine-room Southampton "cottage." "Occasionally I am more messy than Mark is," says Duane. "That annoys him." Hampton admits it: "I am bossy in every way."

One person he doesn't boss, however, is Barbara Bush. He has tailored his English country style to her "classic Yankee taste" and has even made an allowance for the 30 stuffed animals she keeps for her twelve grandchildren in the family room on the top floor. "It's not the Mark Hampton touch," he says. "It's more the Barbara Bush touch."