Betsey Johnson, Coty award winning designing talent of the late 1960s - she used to design for Paraphernalia, then Alley Cat, where her body-clinging T-shirt dress became a classic - bowed out for a couple of years. There were maternity clothes while she was pregnant, amusing kids' clothes (with the colors identified in big letters) when her daughter was born, and only a small collection for the New York boutique Betsey, Bunky and Nini. Now she's back in the fashion business in a big way again, with her own firm, doing all very body conscious clothes, often in stretchy fabrics. Says a colleague, designer Giorgio Sant Angelo, "She's so aware of our times. She's not ahead, she's today. For me, she's Madame Vionnet, Claire McCardell, and Betsey."

Betsey says her clothes are "for girls who can be stars and free about the way they look." And obviously, for the disco crowd who have been trying to put together this kind of look on their own. Her clothes can be found at Up Against the Wall.

You can rent roller skates at $2 an hour in Central Park from Good Skates and skate on over to Bloomies to join the crowd, or disco roll your heart out in Brooklyn, mostly thanks to the new development in roller skate wheels, and the health craze. So no surprise when Fashion Group Inc. opened their spring showing last week with Bill Butler and pals "roller-discoing" on stage in the ballroom of the New York pants and T-shirts, the women in flashy colored body clothes. That opener was followed by a sequence on bodyclothes, all based on the leotard with designs by Betsey Johnson, Rudi Gernreich, Norma Kamali and others.

Other major points in that industry show - suits, bright colors, the wide range of pants for spring, deep slit skirts, sailor suits and sexy clothes for evening.

Speaking of roller skating. Macy's New York has just opened a boutique in the store called the Roller Disco Shop with everything you need to boogie on wheels - skates, skate keys, tutus, the glittziest clothes, even glitter seam pantyhose, and if need be, knee pads.

Sino of the Times - The Canton (China) trade fair has completed its most successful season ever (more than $20 million worth of textiles and apparel sold to Americans, and three new collections of old Chinese jewelry are in Washington at the same moment - Garfinckel's will have the collection of Chinese crafts of Ellen Kiam called the Friendship Collection, including jewelry and objects d'art, new and old; Bloomingdale's has the collection of the Noble Trading Co., ranging from museum quality pieces to lovely oddities including 100-year-old hand-embroidered taffeta baby bibs studded with garnets and amethysts and mandarin nail guards; Full Circle in Alexandria has an antique Chinese jewelry show as well.

Stanley Marcus, who put it Neiman-Marcus on the world map, first attended the Canton Trade. Far in 1972, when he purchased mandarin court robes and antique porcelains for Neiman-Marcus. Marcus, who then got permission to go to Peking, the first U.S. merchant to be permitted on a buying trip there since 1947, was Georgetown University's School of Business Administration's "executive in residence" this week.

Jeremy Rosenau, president of Nannette, infants and childrenswear makers, has been working on China made items for two years, and has just received the first shipment, says that he is very pleased with the results. One big appeal is the price, as well as the quality of the hand embroidery and smocking. Washington stores will have them for spring.

The women's basketball team of the People's Republic of China were in their best blue pantsuits (various shades) for the luncheon in their honor given by The Rev. Timothy Healy, S.J., president of Georgetown University, Wednesday. Not the expected navy cotton variety but blue flat tweed or shadow plaid in wool blend with mock turtlenecks under, and flat black shoes. Skirts are worn only during warm weather and according to Luo Xue Lian, jeans are unheard of.

An extraordinary collection of costume drawings, including some with instructions for the dressmaker, plus decor designs, sculpture, prints and books from dance, theater and opera go on sale later this week at Sotheby Park Bernet in New York. Costume drawings by Alexandre Benois and Boris Anisfeld, Leon Bakst's watercolor drawings of costume designs including his design for the king in La Pisanella with instructions for the dressmaker, plus fashion drawings by Erte, Benito (Eduard Garcia) and a collection of 81 drawings by Christian Dior for La Maison Raphael Couture are among the fashion treasures in this sale.

It's a fresh color palette that shows up in the spring collections in New York and Paris, the main difference being the replacement of all of the off-whites with pure, sparkling white and the injection of bright colors. It means that a new make-up palette is called for as well, staring with a bright red lipstick. "Not so simple," says Carol Phillips, executive vice president of Clinique. "Red lipstick looks sensational on the runway models and photographic models. But when it comes to trying to live with it women will find red lipstick very hard to wear."

Finding the right red is difficult "because of the different tonality of each individual's mouth," says Phillips, and also because "red is so defining. It really calls attention to the mouth and specific shape of the mouth." After 100 color submissions from the chemists, Clinique settled on four different reds, including scarlet and earth red. Phillips expects most women will find the earth red most wearable as it has the most brown in it. Other make-up changes, according to Phillips: a lot of lip gloss for brightness, a beigier, lighter face, brown on the eyes instead of grays and blacks, more brown under the cheekbone. Phillips suggests using loose face powder by pouring it into the hand and scrubbing it into the face to fill every nook and cranny. "It gives a more illuminated, smoother look," explains Phillips.

We got letters - because there are no black models in this year's Neiman-Marcus Christmas catalogue. And we checked it out and it's true. And we asked why, and were told by Philip Miller, Neiman-Marcus president, "It was a dumb mistake. It was done by the person who casts the models for the book and it was dumb."