(FORTUNE Magazine) – Millions of record buyers know the voice of Olivia Newton-John, the Australian pop star who asked the question, ''Have you never been mellow?'' But lately her clothes have been selling better than her records. Newton-John, 40, jumped from platters to patterns in 1983, when she started the Koala Blue women's sportswear boutique in Los Angeles. Through clever marketing and a canny licensing strategy, the company has grown to 27 stores worldwide and $14 million in sales. Newton-John, who runs it with two partners, designs some of the clothes herself. ''I've always liked fashion,'' she says. ''When I shop now, I call it research.'' She opened the first store to help cure her homesickness for Australia. She filled it with novelties from Down Under, but the best-selling items were T- shirts adorned with a koala bear logo. The chain soon began selling brightly colored sportswear lines that were made in Los Angeles but had Aussie names like Alice Springs or Brisbane Check. Newton-John, who hasn't had a hit since she urged her fans to get ''Physical'' in 1981, says her stores are spinning off profits. ''I want the chain to stand on its own,'' she says. ''It mustn't rise and fall on my name.'' Newton-John has the right idea: If Koala Blue stays in the black, she won't have to sing for her supper anymore.