  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 two experiences have different qualia, any version of representationalism implies that, if this scenario is possible, the two experiences differ in representational content. Hence, if the foregoing scenario can be filled out so that (a) the two experiences have the same content and (b) the scenario is possible, then representationalism is refuted.