What is color? On the one hand it seems obvious that it is a property of objects – roses are red, violets are blue, and so on. On the other hand, even the red of a single petal of a rose differs in different lighting conditions or when seen from different angles, and the basic physical elements that make up the rose don’t have colors. So is color instead a property of a mental state, or a relation between a perceiving mind and an object? In Outside Color: Perceptual Science and the Puzzle of Color in Philosophy (MIT Press, 2015), M. Chirimuuta defends an ontology of color that aims to capture the ontology implicit in contemporary perceptual science. Chirimuuta, an assistant professor of history and philosophy of science at the University of Pittsburgh, argues for color adverbialism, in which color is a property of an action-guiding interaction between an organism with the appropriate visual system and the environment. On her view, color vision is not for perceiving colors; it provides chromatic information that helps us perceive things.