An adequate ontology of color must face the empirical facts about perceptual variation. In this paper I begin by reviewing a range of data about perceptual variation, and showing how they tell against color physicalism and motivate color relationalism. Next I consider a series of objections to the argument from perceptual variation, and argue that they are unpersuasive. My conclusion will be that the argument remains a powerful obstacle for color physicalism, and a powerful reason to believe in color relationalism instead
