Hi Brent,
I just finished this section, which relays what I think may be an important difference between functionalism and other identity/intrinsicist theories. Namely, that according to functionalism, there are an infinite number of potential, distinct, kinds of qualia.
My write up on this is pretty brief, but it relates to some of the things that came up recently, such as how colors seem to people (or other entities) having more or fewer kinds of photoreceptors:
I include an image of how dichromats (most mammals) see the world, which cannot distinguish green from orange. And also, I reference the mantis shrimp, which has the most complex eyes in the animal kingdom, and an incredible 16 kinds of photoreceptors.
Jason