 If the thought experiment describes a genuine possibility, there are at least three ways to modify the simple view: (i) Deny that content supervenes on phenomenology, allowing that two experience with the same color phenomenology can nonetheless differ in content. One version of this response says that the phenomenal difference is a ‘raw feel’ or ‘qualia’ (see Block 1990, 1996); another version holds that a single color property can present itself to a perceiver in phenomenally different ways. (ii) Hold that there are phenomenal differences between G-experiences that represent redness and G-experiences that represent greenness, so that ‘G-experience’ does not pick out a fully determinate phenomenal type An example of this response is externalism about phenomenology, defended by Lycan 2001 and Dretske 1995. (iii) Hold that there are contents shared by G-experiences that represent redness and G-experiences that represent greenness. This response is developed by Thau 2002, who offers a Russellian version of it; Chalmers 2004, who offers a Fregean version of it; and Shoemaker 1994, 2005, who offers another Russellian version of it.