No, red is an abstraction that is not based on knowledge of how colors work.
it is an abstraction based on how our biological eyes work (this implies "knowledge" of physics)
so it is indirectly based on knowledge of how color works, it's simply not physics as we understand it but it's "physics" as the biology of the eye "understands" it.
red is an abstraction whose connection to how colors work is itself another abstraction, but of a much deeper complexity than 'red' which is a rather direct abstraction as far as abstraction can go nowadays
There is absolutely no knowledge needed for someone to point to something that is red and say "this is red" and then for you to associate things that roughly resemble that color to be red.
Understanding the underlying concepts is irrelevant.
Except I could think they mean the name of the thing, the size of the thing or a million other things. Especially if i have no knowledge of the underlying concept of colors.
"How colors work" is dubious.
In physics, color has been redefined as a surface reflectance property with an experiential artefact as a mental correlate. But this understanding is the result of the assumptions made by Cartesian dualism. That is, Cartesian dualism doesn't prove that color as we commonly understand it doesn't exist in the world, only in the mind. No, it defines it to be the case. Res extensa is defined as colorless; the res cogitans then functions like a rug under which we can sweep the inexplicable phenomenon of color as we commonly understand it. We have a res cogitans of the gaps!
Of course, materialists deny the existence of spooky res cogitans, admitting the existence of only res extensa. This puts them in a rather embarrassing situation, more awkward that the Cartesian dualist, because now they cannot explain how the color they've defined as an artefact of consciousness can exist in a universe of pure res extensa. It's not supposed to be there! This is an example of the problem of qualia.
So you are faced with either revising your view of matter to allow for it to possess properties like color as we commonly understand them, or insanity. The eliminativists have chosen the latter.
Love your perspective. It reminds me of this argument I’m working on about Turing machine qualia. Maybe my argument is just Searle in disguise? https://x.com/jchris/status/1815379571736551923?s=46&t=8A60w...
There's no definition for "color" in physics. Physics does quantum electrodynamics. Chemistry then uses that to provides an abstracted mechanism for understanding molecular absorption spectra. Biology then points out that those "pigments" are present in eyes, and that they can drive nerve signals to brains.
Only once you're at the eye level does anyone start talking about "color". And yes, they define it by going back to physics and deciding on some representative spectra for "primary" colors (c.f. CIE 1931).
Point being: everything is an abstraction. Everything builds on everything else. There are no simple ideas at the top of the stack.
> There's no definition for "color" in physics.
This is unnecessarily pedantic. Your explanation demonstrates that.
> There are no simple ideas at the top of the stack.
I don't know what a "simple idea" is here, or what an abstraction is in this context. The latter has a technical meaning in computer science which is related to formalism, but in the context of physical phenomena, I don't know. It smells of reductionism, which is incoherent [0].
> To untutored common sense, the natural world is filled with irreducibly different kinds of objects and qualities: people; dogs and cats; trees and flowers; rocks, dirt, and water; colors, odors, sounds; heat and cold; meanings and purposes.
It's too early to declare that there are irreducible things in the universe. All of those things mentioned are created in the brain and we don't know how the brain works, or consciousness. We can't declare victory on a topic we don't fully understand. It's also a dubious notion to say things are irreducible when it's quite clear all of those things come from a single place (the brain), of which we don't have a clear understanding.
We know some things like the brain and the nervous system operate at a certain macro level in the universe, and so all it observes are ensembles of macro states, it doesn't observe the universe at the micro level, it's then quite natural that all the knowledge and theories it develops are on this macro scopic / ensemble level imo. The mystery of this is still unsolved.
Also regarding the physics itself, we know that due to the laws of physics, the universe tends to cluster physical matter together into bigger objects, like planets, birds, whatever. But those objects could be described as repeating patterns in the physical matter, and that this repeating nature causes them to behave as if they do have a purpose. The purpose is in the repetition. This is totally inline with reductionism.
> I don't know what a "simple idea" is here
To be blunt: it's whatever was in your head when you decided to handwave-away science in your upthread comment in favor of whatever nonsense you wanted to say about "Cartesian dualism".
No, that doesn't work. If you want to discount what science has to say you need to meet it on its own turf and treat with the specifics. Color is a theory, and it's real, and fairly complicated, and Descartes frankly brought nothing to the table.