[phaefele]

In the qualia / physical world distinction, I wonder if there are good reasons we see things the way we do.

Take colors: colors map to wavelengths of light. I wonder if there is a good reason for our perceptions of color to have red be lower frequency and indigo be higher frequency. I guess what I'm wondering is if our brain mapped these differently, it would be suboptimal in some way - perhaps the 'mixing' of colors would work out less 'well' (e.g. red+yellow=orange wouldn't work in the new layout as well.) If so, then perhaps one could use evolutionary selection pressures as an explanation to lead us to the qualia we have.

Or have I perhaps just missed the whole point?

[sunir]

Indeed! Your visual system has a red-green band and yellow-blue band (cf Hering theory). The colour wheel is a result of the physical structure of your visual system. Purple itself is not a spectral colour but a hallucination caused by red and blue firing simultaneously.