Spectrum inversion scenarios help to focus the dispute between representationalists and their critics. (Actual cases of shifted spectra can also serve: see Block 1999.) Any version of representationalism is committed to the following thesis. Consider a case of red-green spectrum inversion, and imagine Invert and Nonvert are both looking at the red peppers depicted in figure 6, against a neutral background. Nonvert’s experience has \(Q_{R}\), while Invert’s experience has \(Q_{G}\). Because the t