Move over, Nancy Reagan. This week your husband grabs the fashion spotlight. It may not be for the specific clothes he wears -- like the brown suits, Windsor knots and spread collars, or even the plaid slacks. It's the pastel shades, popular in California, particularly for pleasure clothes, that are the big news, maybe the only news, to surface in men's clothing for spring.

Underscoring the change from Plains to fancy, Chip Tolbert, fashion director of the Men's Fashion Association, the educational and promotional arm of the menswear industry, presented an opening show at the group's annual spring meeting with models in pastel suits. Imagine a butter-yellow suit with white shirt and pastel plaid tie, a grass-green and pinwale cord suit with peach shirt, yellow tie and fair isle sweater including both those colors. For the diehard conservatives, there was a banker's gray suit (pinstriped in rose) worn with a pale-lavender tie and a pink pocket square.

Even had there been a change in the shape of suits, it might not have been noticed with all the pastels. In fact, the silhouette has swung back from the extremes of big shoulders and extra-wide or extra-narrow lapels to something quite safe and familiar in between.

But the place where these pastels seem to work is in sportswear and accessories like the new crop of summer sweaters, the variations on the Lacoste knitted polo shirt, and even skinny ties. In small doses, these pastels should even find their place in Washington, at least on weekends.

If the lingerie shades and the blushing pink (of the suits, not the models) are not all that familiar in menswear, other pastels are. The word preppie may be dropped from the fashion vocabulary for spring, but traditional preppie styles and colors show up in such fabrics as seersucker and cotton cord, madras and cotton oxford plus all the pastel shetland sweaters.

American men have always worn color, said designer Alan Flusser, who has tamed his bright tones of last fall into softer colors for spring. Even conservative stores such as J. Press and Brooks Brothers have always sold some of their classics in pastels.

Not everyone down here is gung-ho about the pastel push. "Look at those trousers," said William Thourlby, a former actor who appeared with Ronald Reagan in "Death Valley Days" in 1960. He was pointing to a boyish-faced model in pink pleated trousers that fit snugly over his hips. "If they make him look double in size in the beam, imagine what they would do for me," said Thourlby, who claims he is a Reagan-sized 42 or 43 long. Thourlby, author of "You Are What You Wear," said President Nixon had the best formula for dressing. "You never noticed what he had on."

Harry Guinther, president of Richman, a 335-store, moderately priced menswear chain with several stores in the Washington area, has reservations about pastel colors, too. "Designers must make sure that the colors don't look feminine," said Guinther. The particularly risky shades, he said as he watched clothes go down the runway at the Plaza of the Americas Hotel, are the blue-greens and the burgundy tones that look too much like plum.

While the pastels are the big news here, a couple of other changes (or revivals) are slipping in as well: the two-color shirt with a collar of a different color than the body; the white dinner jacket, certainly not as strong as in the '50s but starting back; the wing-collar shirt, well under way but boosted by the Reagan style of dressing up; French cuffs, a Ronald Reagan favorite, and the short haircut with a slight pompadour, inspired by the White House.

Also returning from the '50s is the short-sleeve shirt. "I guess the reason I think it's so ugly is because I think back to those boxy, short-sleeve shirts of 25 years ago," said Tolbert, who believes that with a cutback in air conditioning and hotter summers short sleeves are likely prospects. "I prefer the short-sleeve knit shirt, even with a tie, anyway."

No one expected the Western look to lag behind for spring with Reagan in the White House -- cowboy style, particularly in hats, boots, belts and jeans, gets an added boost.

One item not getting much play on the runway, though it is a Reagan favorite, is the brown suit. Most designers are reluctant to criticize the president -- "I don't want to kill my chances of being invited to the White House right in the first month," said one. But no one is expecting a brown-suit revival. Criticism is not as harsh as from Charles Revson (the late Revlon president) who once said, "Men in brown suits look like s---."

One company familiar with the clothes of the president is Van Heusen shirts, which has revived an ad from 1953 in which Reagan modeled its then-new Century Shirt. According to Maurice Berger, who was then a vice president of Gray Advertising and worked on the ad, the Reagan ad was part of a series promoting the shirt with the wrinkle-free collar. "Remember, that was pre-permanent press and wash and wear," said Berger, adding that movie studios provided stars for ads in exchange for a plug for their movies, in this case, "Law and Order." Berger, now a consultant to the shirt company, wouldn't try to recruit Reagan for a shirt ad today. "I think he's a good bit beyond that," he said, laughing.