Some worry about whether colors might be ineffable qualia and argue that there could be human beings who experience an inverted spectrum — their green is your red, their red is your green — but who use “red” to apply to green and “green” to apply to red. Others argue that it is a mistake to think there is anything subjective about red and that the concept of “experience” is itself incoherent. To use “red” competently is simply to respond to things everybody agrees are red with the word “red”. We can call the first group “phenomenalists” and the second “behaviorists” for want of a better pair of labels.
What both of them — phenomenalists and behaviorists — miss is that red things are alarming and cause us to draw back in alarm, while blue and green things calm us and welcome us in. An experience is neither just an observable response to an objective stimulus nor a featureless internal presentation that can just as easily be swapped with a different internal quale. So the notion of an inverted spectrum makes no sense. The color red could not look green or the color green look red, without a whole lot of other parts of our life being different.
Nobody worries about the inverted hedonic scale problem — the person who feels what we consider painful to be pleasant and what we consider pleasant to be painful but happens to love pain and fear pleasure. Nobody worries about inverted aesthetic scale problem: the person who thinks all things we consider beautiful to be ugly and vice versa but loves to experience the ugly and hates to experience the beautiful. Nobody worries about the inverted truth problem — the person who thinks what we think is false to be true but whose beliefs track the false.
Experiences, beliefs, responses and colors hang together with modes of acting and expressing ourselves. If you want to change one you can but you have to feel your way into all the other things that need to change. Imagination is not as easy as it looks — it’s not just a random collection of conjectures, but a bodying forth of a coherent new creation.