 This problem is related to one that Hardin (1988, 2004) and Cohen (2009) have drawn attention to. It has to do with the problem of identifying, in a non-arbitrary way, normal conditions, and standard observers. The objectivist account requires that we identify the “real” color for object X as a certain causal basis (e.g., the reflectance profile) for the way it appears, to normal observers and in standard conditions. The problem is that, as Hardin has persuasively pointed out, particularly, in Hardin 2004, this cannot be done except in a highly arbitrary way. Not only is there a minority of color perceivers who are anomalous (only slightly, but appreciably so) with respect to normal observers, but there is a considerable statistical spread even within the group of normal observers. For example, the reflectance profile for unique green will differ for different members of the “normal group”. One can decide, of course, on a standard and fix one reflectance profile as green, but the procedure is highly arbitrary. As we have seen, there are few interesting causal powers associated with colors apart from the way objects affect perceivers. (This argument has led to a vigorous debate in the pages of Analysis, see Byrne &amp; Hilbert 2007b; Cohen, Hardin &amp; McLaughlin 2006a,b; and Tye 2006a,b, 2007.)