Even if we think about it in more quantitative terms, with red being defined as having a dominant wavelength approximately 625–740 nanometres, it's a bit of an arbitrary definition isn't it? If we observe a wavelength of 624, objectively we might say it's not red, but someone may still observe it as red considering how close it is to red. Or someone with protanopia won't see anything in those bounds as red either.
We, of course, might disagree, but color-blind people learn which traffic lights are red, green, or yellow, regardless of their perceptual faculties. Because the color is not just what you see, but what you say.
If I sit late at night my desktop walpaper (which is a regular photo with a lot of blue sky) becomes basically all red if you look at rgb values. But I still perceive the sky in it as blue because other things are "more red" so it looks blue, and because I know sky is blue, and because I remember how it looked before and the change happened slowly.
All of these scream "relativism" to me, in fact the mapping to common moral fallacies is surprisingly direct :) When law changes around you you might not recognize when it got evil. Obeying the law is good because it's the law. When everything around is evil - small evil seems good.
As for language and law - these are arbitrary. "Yellow pages" can be any color, so can "blue screen of death". Green traffic lights are actually blue in some countries.
How does it differ from something that exists subjectively then?
I'd say arguing that colors are like morality is pro-relativism stance.
We don't. For starters there are colourblind people, for seconds there is no specific colour that can be called "red". There is a large and fuzzy category of red-ish colours like blood-red or rose-red.
Even if there is some academic "these light wavelengths are the ones" definition of red that is arbitrary. Aliens might have drawn the lines elsewhere.
To pick an example closer to the morality case: Hunger could equally be called a subjective phenomenon. Aliens may not experience anything like hunger. A rare genetic condition might produce a human who experiences escalating hunger as an escalating degree of pleasure.
But as humans making our way through the real world, we are forced by physical and anatomical reality to see the causes and consequences of human hunger as objective truths.
You didn't consider what I wrote - colourblind people get through life without considering the colour of traffic lights at all. They have to. They are colour blind. The colour of a traffic light as a practical matter is a subjective fact. In fact, the practical colour of a traffic light is more subjective than the philosophical take because at least philosophers can be convinced with a wavelength argument.
I define hunger as the ideal signal that corresponds exactly to the extent of starvation. 'Ideal signal' is almost like sensation or feeling, except it may not be always or in full precision accessible by consciousness. It is a physical signal, or a function from the physical state. Extent of starvation seems objective (after fixing its definition), and so hunger seems objective too (correspondence is exact). By this definition, if you are starved, but don't notice a feeling of hunger, it's that, you still are hungry, just don't notice it.
> What I consider hunger someone else can consider the norm or vice versa.
How can that be? Do you mean definition, or something else? What do you consider hunger?
If you redefine words how you please you can prove anything. What's the point tho?
> What do you consider hunger?
The feeling I sometimes get that I should eat something. It's VERY subjective (for example when I'm fasting I can go a few days without it, but when I'm not - I get it just cause I'm bored and haven't eaten a breakfast).
Otherwise, this question comes down to whether the meaning of the term 'red' is generated objectively or subjectively, which is related to philosophy of language and mind. See article: https://en.wikipedia.org/wiki/Linguistic_relativity_and_the_... .
Chomsky seems to imply that in a moral context, similarly, as humans learn abstract concepts and boundaries from sparse data, we are also carrying out a process of discovery. He seems to skip over the epistemological reasoning.