Knitting pizazz! This ancient craft has a thoroughly modern look these days as designers experiment with vibrant colors, unusual textures, and natural fibers

THE knitting needles in the hands of the woman in the fifth row stopped as she looked up at the speaker. ``I couldn't knit a white jumper,'' Kaffe Fassett said as he held up a long, bulky sweater with more than 100 colors. ``Changing colors keeps you motivated. Use different yarns together to get texture and subtle blending, and the colors will start to sing.''

The plain white sweater disappeared abruptly into the woman's bag.

Mr. Fassett (whose first name rhymes with ``safe'') is a native of San Francisco who has worked in London for the last 20 years designing knitwear known for its exciting blends of colors and textures.

In a recent Boston lecture, he inspired the audience to change their preconceptions about the rules of knitting. He doesn't make sketches, take measurements, or weigh yarn. He just ``plunges right in.''

Originally a painter, Fassett gets his inspiration from everything around him - Oriental pots and rugs, tiled floors, old maps, Turkish fruit bowls, candy papers, and woodpiles in Norway. His 1985 book, Glorious Knits (published in the United States by Clarkson N. Potter Inc., $22.50), an international best seller, reflects this eclectic taste.

Two of Fassett's new designs can be found in a recently released book, Summer & Winter Knitting (the Westminster Trading Corporation, Amherst, N.H., $24.95). In it, author Stephen Sheard brings together 20 of Britain's top knitwear designers, each of whom contributed a summer cotton and a winter wool design.

The book is divided into classic and modern sections. Besides Fassett, the classics section includes such popular designers as Sasha Kagan and Jean Moss. Ms. Kagan's two animal designs continue the whimsical, vibrant quality established in her earlier work. And Ms. Moss, the genius behind much of Ralph Lauren and Laura Ashley knitwear, shows off two intricate sweaters designed for both men and women.

Among the moderns are Sally Muir and Joanna Osborne (whose company is known as Warm and Wonderful), who designed the sheep sweater that Princess Diana made famous. Bodymap, the company name of designers Stevie Stewart and Dave Hulah, add three designs that are rather funky and outrageous, yet highly fashionable.

Many of the knitwear designers whom Mr. Sheard approached for the book were quite wary of the project at first. They're much more interested in selling the garments themselves instead of the patterns. But it was their respect for Fassett, a personal friend of Sheard's, that got them to join into the project.

``There was very much the Bob Geldof approach [for the book],'' Sheard concedes. ```Would you come to my concert? Elton John's coming.'''

So why are there so many wonderful knitwear designers in Britain? ``We have a long knitting history,'' says Sheard. ``It goes back to the Shetlands, guernseys, and arans [traditional sweater designs] knitted for centuries in the fishing villages in North Yorkshire.'' And there's the tremendous number of British knitters, tens of thousands of whom work for the designer knitters. Moss alone employs more than 4,000 - quite a large amount for the Yorkshire area.

There are at least 11 million knitters in Britain, representing about 40 percent of the female population - ``with a few blokes thrown in there,'' says Sheard. There aren't really statistics for the US, although it's assuredly much fewer.

Happily for the knitwear designers, there has been a definite resurgence toward natural fibers and more fashionable knitting.

There is, of course, a world of difference between designer knitting and ordinary knitting.

``Designer'' knitters focus on the quality and integrity of a design and the use of natural fibers to make their clothing as different from factory production as possible. Many ``common'' knitters are very skilled, but tend to use acrylic yarns.

``The garments can stand up by themselves,'' laughs Sheard, who owns a natural fiber yarn company, Rowan Yarns, in his native Yorkshire.

Jacquelyn Katzenstein, who owns the Wild & Woolly Studio in Lexington, Mass., is also happy about the changing attitudes toward knitting. Her shop not only sells high-quality natural yarns, but also gives classes and a lot of personal help to knitters.

``These are the kind of yarn stores,'' says Ken Bridgewater of the Westminster Trading Corporation, ``which are growing very nicely - they have a clear definition of where they're going.... [there's] a lot of design content in what's being sold.''

``The bejeweled, glitzy, glamorous look is out,'' notes Sheard. ``Knitting must go forward with the mood, the times - toward feeling informal, relaxed, casual.'' While there are quite a number of knitting stores closing, the ones that are growing cater to the changing desires of knitters - stocking natural yarns, designer knitting books, and new equipment.

Knitwear designers such as Fassett are inspiring this new breed of knitters. And not only are knitters using new and natural yarns, they're also becoming more creative. More of them are making up their own patterns rather than trying to find exactly what they like in a pattern book. Or, as often happens with Fassett's patterns, people use his patterns, but pick their own colors. ``Kaffe is not a good salesman for his kits,'' says Mr. Bridgewater.

More men are knitting now, too, according to Ms. Katzenstein of Wild & Woolly. ``They tend to be engineers, doctors, dentists, who are all precise and use their hands a lot,'' she says.

Most of her customers, in fact, are career people who knit because it's relaxing and portable. And then there are the people who just buy all the new books, or all the latest gadgets. Other people buy so much yarn ``they couldn't possibly live long enough to knit what they've bought,'' says Katzenstein. ``They're yarn junkies!''

Fassett rivals them all, however, with his collection of thousands of skeins of yarn. He has worked closely with Rowan Yarns since its early days in the late '70s, choosing and creating new colors and textures.

Together, they have produced many of his designs in kit form. Some of the designs in ``Summer & Winter Knitting'' can also be obtained as kits.