Qualia aren't what you are probably thinking they are ...

There really is no "blueness" to blue, or "redness" to red.

Consider this strawberry illusion.

https://boingboing.net/2017/03/01/the-strawberries-in-this-p...

When you look at those strawberries you experience the quale of redness, yet they are not red, so this quale isn't directly related to the color of the object you are looking at.

The qualia of colors is just a result of our ability to differentiate surfaces based on the differing inputs our brain receives, but as illusions like this show this is really a function of memory/prediction rather than actual color. The (subjective) quale of redness is something that your mind creates by comparison/recall. You see those strawberries as red because it reminds you of red strawberries. Different colors have to look like something, and since color is basically just a differentiator, it only has any meaning in relation to things of other (similar or different) colors. Grass-green leaves have the quale of grass-green because they remind you (same neural input) of grass.

It's interesting to note how arbitrary (and poor!) our perception of color is, since we only (usually) have three color detectors (retinal cones) tuned for overlapping portions of the frequency spectrum.

http://hyperphysics.phy-astr.gsu.edu/hbase/vision/colcon.htm...

Even if we're looking at a pure red object (say 600-650nm light wavelenth), our green (center frequency) detector is also firing too, since that's just the way our eyes are built - we're not really directly detecting colors but just have those three detectors firing to different degrees, which allows us to differentiate a lot of colors. Some people have 4 types of cone rather than 3, and are therefore able to differentiate colors that would look the same to normal people... There is nothing absolute about our perception of color - just an ability to differentiate so some degree or another.

It's interesting to contrast our poor color detection with our much better auditory frequency detection. Our ear basically has a whole bunch of specific frequency detectors (hair cells of the inner ear), almost like doing an FFT of the input signal. Our color sensing "could" have been like this too, but instead evolution has found out that, for us, these three overlapping light frequency detectors is good enough, but for sounds we need to be much more discriminative.

It's an interesting thought experiment to consider what it would be like if we had another way to differentiate surfaces other than by color (or texture). Imagine if we had an ability to remotely detect (see) surface temperature, but not by a thermal imaging device that maps temperature to colors. You could imagine someone making goggles that had directional temperature sensing ability and tracked our gaze direction, such that it output temperature data for a patch around our center of gaze, and fed this data into some part of our cortex via a neural-link like device. What would the qualia of this new sense be like?! Just like color, it would have to "look" like something, and different temperatures would have to look different, but the resulting quales of "hot" and "cold" surface properties would just be whatever our mind recalled when exposed to those inputs. I'd guess that all hot objects would just look "hot" and remind us other other hot objects, just as all red objects look "red".