Mbs Technical Report 14 - 02

Color is an inner, highly subjective experience only triggered by properties of light from the external world. Actual color perceptions are inextricably linked to (i) visual processing properties of observers that can vary greatly across individuals, and (ii) minor changes in viewing circumstances. Thus, it can be argued that color is not of this world, or, that color is not a veridical, or even an unbiased index of object properties. To illustrate this assertion we present empirical results on the visual processing of four individuals. All four of these individuals have excellent color perception (as shown by standardized color vision assessment procedures). Two of the individuals are considered standard “normal” trichromat observers, while the other two are “potential tetrachromat” observers – that is, observers with a genetic potential for an extra class of visual pigments used for color vision. By comparing such observers’ color perception performance, and their artistic uses of color, we illustrate how wide the definition of “normal” human color vision actually is, and how some observers that are typically classified as “normal” might actually experience a world of color beyond what the average color vision normal human experiences. We relate our results showing considerable variation in normal color experience to the question of what portions of reality actually provide the ground-truth for the world's perceived color palette. We also considered how we should conceptualize color meaning when two individuals with different visual processing experiences sit down to discuss the beauty of, for example, a sunset or a field of flowers. Our empirical results strongly support the idea that, above and beyond objective reality, constructive mental processes are the true arbiter of color experience, that color sensations should not be thought of as a true reflection of reality, and that color does not serve as an unbiased indicator of properties in the external world.