The inverted spectrum thought experiment posits that you (the subject) wake up one morning to find that your colour spectrum (or some part of it anyway) has inverted. This experiment has important implications for the idea of "qualia". While we may not have a way to manipulate qualia directly, this experiment still seems like it would be valuable to conduct. In Daniel Dennett's version of the experiment - "alternative neurosurgery" - he points out that you wouldn't know if your optic nerve was messed with, or your memories, and I would extend this to any apparatus that inverts spectrum at any point along the sensory pathway.
I imagine that the technology to develop goggles (similar to the prism glasses, colour filters, distortion lenses, etc, used in perceptual adaptation experiments) that invert colour is available. However, I have not seen any reference to such an experiment being conducted. Has it? And if not, why not? Are there practical limitations?
It seems to me that the construct of qualia hinges on there being some property of experience that is independent of behaviour/function/physical state, and the subjective experience of colour is often touted as a perfect example of this, via the inverted spectrum experiment. So then the practicality of this experiment - whether or not an inversion of some kind is possible without a functional impact - is crucial. If the experiment cannot be conducted because no inversion exists that can be done without functional impact, then it would constitute a severe blow to qualia as independent of function, and conversely, if it can be done, and the effect shown to be independent of behaviour, then it would surely be a problem for functionalism... So why not try it?