Business Notes SPORTSWEAR

Surfers and snowboarders have been blinded lately by a dazzling brilliance. It's not glare from the snow or water, but the neon-colored outfits of their companions. From the California coast to the Alps, the hottest look under the sun is the "acid bright" sportswear produced by the O'Neill company of Santa Cruz, Calif. The parkas, swim trunks, rucksacks and other splashy items are hard to miss, since O'Neill emblazons them with the company name in huge letters. O'Neill's sales reached an estimated $100 million last year, up more than 30% from 1988.

Started as a wet-suit manufacturer in 1952, O'Neill branched into sportswear five years ago with a line of trunks and tops. Clothes for snowboarding were a natural extension, since that sport is favored by many surfers. O'Neill's winterwear ranges from insulated shells ($90) to full suits made for extra- strenuous performance ($350).