It almost could have been a scene right out of "Gone With the Wind." There were straw hats and parasols, long white dresses and pinafores swaying languidly on the lawn, and there was actress Olivia de Havilland fanning herself in a corner.

Actually, it was the Salvation Army Auxiliary's 27th annual garden party Saturday at the Swiss embassy and De Havilland was the star attraction. The actress declared the party open and then spent the next three hours at a card table signing autographs for $1 each.

De Havilland, who has lived in Paris since her marriage to Paris Match editor Pierre Galante in 1955, admitted she was unprepared for the heat of a Washington summer. "Now I know what the bonnets were for," she said, flapping the wide brim of her white hat.

Nearly 40 years after the Atlanta premiere of "Gone With the Wind," Olivia de Havilland still admires Melanie, the part she played. She was delighted Saturday when people would come up to her and say such things as, "I've seen 'Gone With the Wind' eight times!"

"She (Melanie) was a very strong woman - loving people are very strong. She and Ashley had the perfect marriage, and a very satisfactory sex life. If you watch in the movie, the smiles . . .oh, definitely."

Olivia de Havilland tugs at the brim of her big white hat as she speaks about Melanie, her constant companion for four decades. She slips in and out of Melly's sugary Georgia accent, her eyebrows raised in exaggerated innocence - just the kind of look Scarlett would have used on an adoring beau.

But De Havilland admits that living side by side with her celluloid youth has its drawbacks. Her fans say - sincerely - that she doesn't look a day older than she did in 1939, when "GWTW" was released. They believe she is as beautiful as ever. The comparison is continuous, the "acid test," she calls it.

A bemused amusement, and a kind of affection, come into her eyes when she is handed old posters and movie stills of herself to be autographed. She studies the young De Havilland as she might an unidentified actress, gauging the eyes, the mouth, the hair.

The line of fans Saturday was endless, but De Havilland's smile never faltered and her attention never appeared strained by the compliments and handshakes. Occasionally she spoke privately in French to consultant Pierre-Frantz Chapou, her host and guide for the weekend.

Her signature, which she designed and practiced as a child in preparation for fame, is round and generous, almost voluptuous. "Big and round!" she laughs. "Just like me! I don't mind if you put that in the article!"

She is disarmingly frank about her life and her work. She answers even the warhouse questions about the long-standing fued with her sister, Joan Fontaine, but not entirely seriously.

"I am 15 months older than she, and she does not treat me with the proper respect," says the 61-year-old de Havilland, drawing herself up straight. "Diplomatic relations have been broken off, and if they're ever reinstated, it will only be temporary. We're just such different personalities that there's bound to be a crisis. I think my sister enjoys them actually, she creates them so often."

De Havilland is thinking of moving back to the United States, possibly to Washington. "Because it's a capital, designed by a Frenchman, on a river, with a cosmopolitan community (like Paris). It would provide a continuity in my life.

"And it would mean I could keep my personal life and my professional life separate. That's why my life in Paris was so successful, I had a private life. That's nourishing and necessary for me."

She and her husband, who have been legally separated for many years, will be divorced by the end of the year. Their daughter is graduating from law school.

"There are many too many bedrooms in the house," she says softly. "I just need a place for me, a snug place."

She is about to go on, but a fan interrupts for an autograph. "Do you have a dollar? It's for the cause," says De Havilland sweetly. Just like Melanie used to do.