I'm reporting what the science says. — Michael
Well, you're reporting what the writer says. If the author is a scientist, then you're reporting what a scientist says. And they... and we... are theorizing from observation/experiment. Not all scientists agree on the theoretical extrapolations you're presenting. Theoretical physics is philosophy. So, it seems to me that you're reporting on both, the experiments, and the philosophical explanations thereof. Those are flawed as well, as I'll address shortly.
First...
Here's what I'm saying: The biological machinery under consideration - in complete and total absence of external stimulus - is inherently incapable of seeing, dreaming, or hallucinating anything at all, colors notwithstanding. Seeing, dreaming, and hallucinating colors takes more than just the biological structures.
Second...
I'm not disagreeing that hallucinations and dreams happen even though there is no typical external stimulus present. I mean, hallucinating and dreaming red pens, never includes a red pen. It is only after one has seen color, that can one hallucinate and/or dream that color. It is during dreams and hallucinations that the same biological structures behave as if they were seeing a red pen, not the other way around. There is an existential dependency at hand here. It's important.
Third...
If there were no cake, then there could have never been anyone smelling one. If no one ever smelled a cake, there could never have been anyone dreaming or hallucinating cake smells. Likewise, if there is no creature capable of smelling cakes, there could have never been cake smelling, even if there were plenty of cakes being baked. It a complex process, replete with necessary elemental constituents.
So...
It takes more than just biological machinery. It also takes more than just cakes. Hence, to isolate only one necessary element in a complex process is to lose sight of and/or grossly neglect the fact that it's a process, and that process consists of different things, all of which are necessary for the emergence of seeing colors and smelling cakes.
You want to ignore the fact that dreams and hallucinations are existentially dependent upon veridical perception, excise the biological machinery from the rest of the process, and then claim that all three consist of only that machinery.
Depending upon one's notion of physiological sensory perception, it could sensibly and consistently be said that smell and color are both inherent in distal objects. Newton came close until positing "sensation". Colored things possess mind independent physical properties that are inherently capable of being seen as colored by a mind so capable. I think Searle holds something like that, but I'm sure his is more nuanced.
I personally reject the idea that color exists at all in the complete absence of both/either colored things and/or creatures capable of seeing color.