(FORTUNE Magazine) – While striking Caterpillar workers observe no discernible dress code (see photo above), trendy dressers like the man at right are putting the company on the fashion map. Men and women are togging out in work clothes that not only are colored black and yellow, Caterpillar's corporate hues, but also are emblazoned with the company's logo. Big Smith, of Carthage, Missouri, is making the duds under a license from Caterpillar. Retailers that sell them include Sears Roebuck, which charges $65.99 for quilted bib overalls, $52.99 for bomber jackets, and $39.99 for vests. Sears sells the Cat line in some 20 stores, and sales have been brisk, reports Robert Young, the chain's buyer for men's work wear. He plans to put the duds into more stores next fall. The line offers an update to the terra-cotta- and indigo-colored denim work wear that caught the attention of urban hipsters and dance club regulars a few years ago. Says James Truman, editor-in-chief of the men's fashion magazine Details: ''Work clothes have become everyday chic, because kids today pump up at the gym. They can't fit into the skinny black jeans that rock-and-rollers wore a decade ago.'' Big Smith expects sales of the Cat line to quintuple to $5 million in 1992, helped by the planned introduction of heavy-duty shorts (about $27) this spring. Caterpillar's take: an estimated 7%.