 On the assumption that experiences with the same color phenomenology will have the same color content, this thought experiment challenges the simple theory we began with, since it purports to describe a case in which a G-experience is an experience of veridically seeing red. Defenders of the simple theory may reject the assumption. Alternatively, they may challenge the part of the thought experiment that purports to describe inverted qualia without illusion. That is, they may challenge the idea that Invert’s G-experiences veridically represent redness, rather than non-veridically representing greenness. In response to this challenge, most interpretations of this thought experiment build in substantive assumptions about what sorts of conditions are sufficient for making it the case that experiences represent one color property rather than another. It is standardly said that the phenomenally different color experiences come to represent the same property due to externalism about color contents of experience, whereby when a type of experience stands in the right sort of causal relations to, say, redness, this suffices to make experiences of that type represent redness.