Grace Jones dressed totally in black last week for the Kenzo show, the grand finale of the week-long fashion festivities here. "I love black. It makes my eyes look big and my lips look red," said the entertainer, wearing a skinny wool dress by Azzedine Alaia and a padre hat with ear flaps.

For Jones and many clothes-conscious visitors to the spring ready-to-wear shows, black is an important wardrobe scheme--the important new fashion off the runways, and a sign as significant as anything on the runways.

"I opened the door to my closet at the Ritz this morning," said Marjorie Deane, chairman of Tobe Associates, Inc., an international fashion consulting firm, "and it looked like the clothesline of a Portuguese widow. Everything is black."

But the black garb worn to the shows in the Louvre courtyard and in the chichi dinner spots hardly resembles "widow's weeds." And, certainly, that doesn't mean the little black dress. On sunny days, black wool ponchos and black wool jackets, huge black sweaters and funny trousers and shawls are popular; rainy days bring out shiny black raincoats, some wool ponchos and others in pressed plastic that looks like reptile skin. Rain or shine, black leather skinny skirts a la Saint Laurent are everywhere, and so are black leather pants for men and women.

While a shock of red from hose, shoes or an occasional scarf offers some contrast, most accessories are black, too. The popular hat here, as in New York, is swiped from men, Al Capone in particular, and is black, of course.

The punks, who may have inspired all this black, add to the crowds with their own black, often topped by licorice-colored dyed hair.

Ellin Saltzman, fashion director of Saks Fifth Avenue, who was wearing head-to-toe black at the Valentino show, said, "It simplifies my life." Saltzman has been partial this season to the easy pieces of big cashmere sweaters, pants, skirts and coats from the New York designer Zoran, the pet of all the American fashion mafia here. "If you wear only black, then you don't have to worry about bringing lots of accessories to match everything," said Saltzman, who admitted that she was traveling with five pairs of shoes, all black.

At the Chanel collection, Harper's Bazaar editor Noonie Moore was wearing black and a very dark gray -- almost black. Her outfit was also by Zoran. "Wearing a color complicates your life when you travel," she said. But last week at the shows in London she bought herself a scarlet shawl. "I needed some relief from all the black."

Japanese editors and buyers, usually more avant-garde than the conservative Americans, are all in black. At the top of the Japanese lists are huge wrap jackets by Issey Miyake, black sweaters from Comme des Garc,ons, and black cotton workers' trousers, all usually worn with flat, black shoes.

Midori Kitamura, assistant to Issey Miyake, said that, except when she wears jeans and a white T-shirt, black takes the worry out of making a choice. "It is good with the Japanese complexion and hair," she added.

Suzy Wilner, who heads the chic shop Solis in Lyons, France, said she can't resist black either for herself or when she buys for the shop. And when she buys a color these days, she likes it best in combination with black, like blue and black or brown and black.

Argentinian Robert Deborik, who owns the successful London shop Regine's (and a new one that just opened on Melrose Avenue in Los Angeles), likes black for himself and his clients. "Like I told Queen Noor of Jordan , even royalty needs to uncomplicate its lives by wearing black," Deborik said. He added that he persuaded Elizabeth Taylor to start wearing black and helped her select a black suede outfit by Italian designer Gianni Versace.

"There is no better color than black to show off false jewelry," insisted Deborik, who one day last week was wearing a black leather jacket from Versace with black trousers, shoes and socks, and a red plaid shirt by Ralph Lauren. He laughed at being caught out of his all-black uniform, which includes black suits by Nino Cerruti and black sweaters by Gianfranco Ferre and Krizia.

"I own so much black, I now try to buy things that aren't black," observed Sonja Caproni, fashion director for I. Magnin. "It is difficult because my favorite things often turn out to be black."