Cutting-edge nail color is back in style—according to newly released data from research and consulting firm Kline & Company. In its recent report, nail polish was the biggest winner, and the only category to post a double-digit increase, reaching 14.3% growth in 2009. U.S. sales in the cosmetics and toiletries market declined by 0.8% in 2009, not a detrimental drop considering the recent market situation and the last major recession of 1991, when sales declined by 1.9%. The data released...