Tye?s missing shade of blue

Abstract

Pure hues are those that are perceived as not being tinged with any other hue. Pure blue is a blue with no perceived component of green, violet or red. A striking empirical finding is that individuals with normal colour vision disagree about which specific hues are pure. What looks like pure blue to John will look like a greenish blue to Jane. This seems to pose a problem for the common-sense view that colours are properties of physical objects or their surfaces. Tye (2006a) notes that this finding has been used to criticize colour objectivism and representationalist accounts of the phenomenal character of colour experience, and to support projectionist views that hold that 'colour is something we erroneously project onto the world' (2006a: 174). Projectionism includes the subjectivist view that colours are internal states or properties of the perceiver. Tye's broad aim is to offer a scenario that accounts for the empirical finding in a way that avoids projectionism, thus preserving colour objectivism in general and in particular the representationalism about colour that Tye favors. The empirical finding leads Tye to pose 'The puzzle of true [i.e. pure] blue' (2006a: title): John and Jane cannot both be right about which specific hue is true blue, because they disagree about the specific hue. They cannot both be wrong, because that would entail projectionism. But since John and Jane are both normal perceivers, it cannot be the case that one of them is right and the other wrong.1 Tye's solution to the puzzle is to propose that true blue is an objective property of physical objects, surfaces or volumes, but that human colour perception is not acute enough to determine which objects, surfaces or volumes actually have this property. In Tye's scenario, it was evolutionary advantageous for humans to distinguish between coarse-grained or deter minable colours such as blue and green, but not similarly advantageous to distinguish the fine-grained differences between determinate hues, such