Yves Saint Laurent spent decades trying to make white shoes and black legs chic. But it wasn’t until last fall, when designer-of-themoment Miuccia Prada showed white high heeled Mary Janes, that the idea took off, especially in the priciest lines. The shoe design team of Susan Bennis and Warren Edwards are offering 60 percent of their spring collection in white. What’s the appeal? Maybe it’s Seventh Avenues fixation with retro glamour. Or maybe it’s just a match for the trend toward unmatched clothes. “In my mind,” says Ross, “it looks like Minnie Mouse.” That’s OK, since even clunky shoes like Minnie wore are chic, as long as they’re white. Indeed, the folks at Dr. Martens are offering a half-dozen new versions of white Docs, This blizzard may be short-lived. “Our next big trend,” says Edwards, “is florals.” Bet Agassi will look great with cabbage roses on his sneakers.