Many would assume that the classic purple raisin would be high in antioxidants. It is relative to most foods, but the lighter varieties (white and golden) have higher antioxidant content.
ORAC Source
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010