You might think that even if pieces of bread are real, their properties (color, taste, smell, and texture) are not, because these are so heavily dependent on our minds. Many philosophers have thought that nothing in the external world corresponds to people's experiences of colors, eliminating them as real. Their arguments rely on the fact that there is no simple mapping between the space of colors that people experience and the properties of objects that affect how they reflect light of different wavelengths. Paul Churchland has found, however, a way of construing the physical properties of objects that reveals a correspondence between their reflectance efficiencies and people's experiences of colors like red, green, and blue. He describes how the human visual system successfully tracks approximations of the reflectance profiles of objects at a low level of resolution, so that colors can be viewed as objectively real properties of objects even if color vision is highly context sensitive.