Neural representations of perceptual color experience in the human ventral visual pathway

There is no color in light. Color is in the perceiver, not the physical stimulus. This distinction is critical for understanding neural representations, which must transition from a representation of a physical retinal image to a mental construct for what we see. Here, we dissociated the physical stimulus from the color seen by using an approach that causes changes in color without altering the light stimulus. We found a transition from a neural representation for retinal light stimulation, in early stages of the visual pathway (V1 and V2), to a representation corresponding to the color experienced at higher levels (V4 and VO1). The distinction between these two different neural representations advances our understanding of visual neural coding.

However the light source being reflected off of the tomato and into the eyes is no less a relevant part of the scientifc understanding of what is happening. — wonderer1

Of course it's relevant, but it's not colour. Just as stubbing one's toe is relevant to explain pain, but isn't itself pain. Pain and colour are what happen in the head after.

Nothing he says aligns with the mistake your entire philosophical edifice, informed stance, rests its laurels upon. See the top of this post. — creativesoul

My "stance" is repeating what those more knowledgeable of the matter have said:

Maund: "It is this problem that historically has led the major physicists who have thought about color, to hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess."

Newton: "For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour."

Kim et al: "Color is in the perceiver, not the physical stimulus."

Palmer: "Color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights."

Maxwell: "Color is a sensation."

Sir. You most certainly did.

You drew a hard fast equivalency between four different things. When I asked you what the differences were between them the answer was the same.

"Nothing"

That is most certainly to claim that there are no differences!

Fer fuck's sake! — creativesoul

You asked me for the difference between an hallucinated red and a red percept. There is no difference because an hallucinated red is a red percept. I didn't say that there's no difference between seeing a red pen and hallucinating a red pen.

You should try reading more carefully.

But perhaps the generic form of the mistake is in thinking that there can be one explanation that will work for all the many and various ways in which we might use colour words. — Banno

And this is the mistake that you are forever making. This has nothing to do with the various ways in which we might use colour words. This has nothing to do with language at all. This is about vision and whether or not its qualities are mind-independent properties of tomatoes. We naively think they are, but physics and neuroscience has shown that they're not.

The fact that the word "blue" is sometimes used to mean that someone is sad or that the word "green" is sometimes used to mean that someone is inexperienced simply has no relevance at all to the discussion.

It does not follow that there are no differences between hallucinating, dreaming, and seeing red things. — creativesoul

I haven't claimed that there is no difference. We've been over this. They differ in what causes the mental percept.

No, it's not. — creativesoul

Yes, it is. See all the quotes here.

Maund: "It is this problem that historically has led the major physicists who have thought about color, to hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess."

Newton: "For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour."

Kim et al: "Color is in the perceiver, not the physical stimulus."

Palmer: "Color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights."

Maxwell: "Color is a sensation."

How much more explicit does this need to be for you?

“When a mental occurrence can be regarded as an appearance of an object external to the brain, however irregular, or even as a confused appearance of several such objects, then we may regard it as having for its stimulus the object or objects in question, or their appearances at the sense-organ concerned. When, on the other hand, a mental occurrence has not sufficient connection with objects external to the brain to be regarded as an appearance of such objects, then its physical causation (if any) will have to be sought in the brain. In the former case it can “be called a perception; in the latter it cannot be so called. But the distinction is one of degree, not of kind. Until this is realized, no satisfactory theory of perception, sensation, or imagination is possible.” — Richard B

Whether you call it "perception" or not is irrelevant. Call it "blugh" for all it matters. The only thing that is relevant is that the visual quality that we naively think of as being a mind-independent property of a tomato's surface is in fact a mental phenomenon either reducible to or caused by neural activity in the brain, usually in response to optical stimulation by light. This is what the science shows, and no appeals to grammar or beetles in boxes or anything of the sort can prove otherwise.

The point of this example is to show that Russell is concerned about the grammar of colour, so we can get it right about what science is actually investigating. — Richard B

The topic is about perception, not grammar. Science explains perception. This has nothing to do with language at all. We can imagine that we're deaf, illiterate, mutes if it helps you move on from this distraction. We still see colours. I don't need to be able to say "this box looks red" and "this box looks blue" for me to see a visual difference between them. The development of the words "red" and "blue" to name the difference comes after the fact, not before.

colours are systematic hallucinations — jkop

And hallucinations are what? A type of mental phenomenon, not a mind-independent property of tomatoes. Therefore colours are a type of mental phenomenon, not a mind-independent property of tomatoes.

you're having experiences without experiencing anything — jkop

This is such a nonsensical sentence.

Russell is not saying what (I think) you think he's saying. When he says "the sensation that we have when we see a patch of colour simply is that patch of colour" he is saying that colour just is that sensation. This is perhaps clearer in a later work where he says this:

Scientific scripture, in its most canonical form, is embodied in physics (including physiology). Physics assures us that the occurrences which we call ''perceiving objects'' are at the end of a long causal chain which starts from the objects, and are not likely to resemble the objects except, at best, in certain very abstract ways. We all start from "naive realism', i.e., the doctrine that things are what they seem. We think that grass is green, that stones are hard, and that snow is cold. But physics assures us that the greenness of grass, the hardness of stones, and the coldness of snow, are not the greenness, hardness, and coldness that we know in our own experience, but something very different. The observer, when he seems to himself to be observing a stone, is really, if physics is to be believed, observing the effects of the stone upon himself. Thus science seems to be at war with itself; when it most means to be objective, it finds itself plunged into subjectivity against its will. Naive realism leads to physics, and physics, if true, shows that naive realism is false. Therefore naive realism, if true, is false; therefore it is false.

I don't have a copy of Searle, but according to this:

Searle presents the example of the color red: for an object to be red, it must be capable of causing subjective experiences of red. At the same time, a person with spectrum inversion might see this object as green, and so unless there is one objectively correct way of seeing (which is largely in doubt), then the object is also green in the sense that it is capable, in certain cases, of causing a perceiver to experience a green object.

This seems to be arguing that colours are mental phenomena and that the predicate "is red" is used to describe objects which cause red mental phenomena.

On colour, Quine has said this:

But color is cosmically secondary. Even slight differences in sensory mechanisms from species to species, Smart remarks, can make overwhelming differences in the grouping of things by color. Color is king in our innate quality space, but undistinguished in cosmic circles. Cosmically, colors would not qualify as kinds.

Your quote of him is him arguing for eliminative materialism, which I have previously accepted is a possibly correct account of so-called mental phenomena (e.g. pain just is a type of brain activity, and so colours just are a type of brain activity).

I've no idea how you arrive at the notion that color is nothing but a mental percept — creativesoul

It's not my conclusion; it's what the science says, and I am simply reporting on that. I have no idea why you and others think that you can figure out how perception works by sitting in your chair and thinking really hard.

It's you who are claiming that the tomato is red but not really red; these are your words — Banno

They're not my words. I said that the tomato does not have the property that it appears to have. The property that it appears to have is in fact a subjective quality, and so is a percept, not a mind-independent property of material surfaces.

You are showing yet again that you are equivocating. As you have mentioned before, the predicate "is red" doesn't just mean one thing. What the dispositionalist means by "the tomato is red" isn't what the naive colour realist means by "the tomato is red". According to the former meaning, "the tomato is red" is true. According to latter meaning, "the tomato is red" is false.

My concern isn't with the sentence "the tomato is red" precisely because the sentence is used to mean different things by different people (and you haven't explained what you mean by it); my concern is with the nature of a tomato's appearance. This is explained by physics and physiology, not by language, and eliminativism is consistent with the science (with projectivism explaining the way we think and talk about colours).

I have seen you do little more in this thread than make arguments from authority. — Leontiskos

Yes. Perception cannot be explained by armchair philosophy. It can only be explained by physics and physiology, and so I am simply reporting on what the scientists have determined. I'll do so again:

Vision science: Photons to phenomenology:

People universally believe that objects look colored because they are colored, just as we experience them. The sky looks blue because it is blue, grass looks green because it is green, and blood looks red because it is red. As surprising as it may seem, these beliefs are fundamentally mistaken. Neither objects nor lights are actually “colored” in anything like the way we experience them. Rather, color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights. The colors we see are based on physical properties of objects and lights that cause us to see them as colored, to be sure, but these physical properties are different in important ways from the colors we perceive.

Color:

One of the major problems with color has to do with fitting what we seem to know about colors into what science (not only physics but the science of color vision) tells us about physical bodies and their qualities. It is this problem that historically has led the major physicists who have thought about color, to hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess. Oceans and skies are not blue in the way that we naively think, nor are apples red (nor green). Colors of that kind, it is believed, have no place in the physical account of the world that has developed from the sixteenth century to this century.

Not only does the scientific mainstream tradition conflict with the common-sense understanding of color in this way, but as well, the scientific tradition contains a very counter-intuitive conception of color. There is, to illustrate, the celebrated remark by David Hume:

"Sounds, colors, heat and cold, according to modern philosophy are not qualities in objects, but perceptions in the mind." (Hume 1738: Bk III, part I, Sect. 1 [1911: 177]; Bk I, IV, IV [1911: 216])

Physicists who have subscribed to this doctrine include the luminaries: Galileo, Boyle, Descartes, Newton, Thomas Young, Maxwell and Hermann von Helmholtz. Maxwell, for example, wrote:

"It seems almost a truism to say that color is a sensation; and yet Young, by honestly recognizing this elementary truth, established the first consistent theory of color." (Maxwell 1871: 13 [1970: 75])

This combination of eliminativism—the view that physical objects do not have colors, at least in a crucial sense—and subjectivism—the view that color is a subjective quality—is not merely of historical interest. It is held by many contemporary experts and authorities on color, e.g., Zeki 1983, Land 1983, and Kuehni 1997.

Neural representations of perceptual color experience in the human ventral visual pathway:

There is no color in light. Color is in the perceiver, not the physical stimulus. This distinction is critical for understanding neural representations, which must transition from a representation of a physical retinal image to a mental construct for what we see. Here, we dissociated the physical stimulus from the color seen by using an approach that causes changes in color without altering the light stimulus. We found a transition from a neural representation for retinal light stimulation, in early stages of the visual pathway (V1 and V2), to a representation corresponding to the color experienced at higher levels (V4 and VO1).

Opticks:

The homogeneal Light and Rays which appear red, or rather make Objects appear so, I call Rubrifick or Red-making; those which make Objects appear yellow, green, blue, and violet, I call Yellow-making, Green-making, Blue-making, Violet-making, and so of the rest. And if at any time I speak of Light and Rays as coloured or endued with Colours, I would be understood to speak not philosophically and properly, but grossly, and accordingly to such Conceptions as vulgar People in seeing all these Experiments would be apt to frame. For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour.

They are literally saying "color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights", "color is a sensation", "color is in the perceiver, not the physical stimulus", and "For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour."

I cannot be misrepresenting them by quoting their own words. They mean exactly what they say.

Your only retort seems to be that we talk about colours as if they are properties of pens. And yes, we often do. And we're wrong, as the science shows.

When we speak about the pen we are speaking about the pen, not about percepts. Pens and percepts are two different things. Maybe you (erroneously) think everyone should replace all of their color predications about pens with predications about percepts, but this in no way shows that when people talk about red pens they are doing nothing more than talking about percepts. — Leontiskos

Yes, and that's the fallacy. See the SEP article on color:

On a third view, Color Projectivism, the qualities presented in visual experiences are subjective qualities, which are “projected” on to material objects: the experiences represent material objects as having the subjective qualities. Those qualities are taken by the perceiver to be qualities instantiated on the surfaces of material objects—the perceiver does not ordinarily think of them as subjective qualities.

This is what we naively do, and physics and neuroscience has proven it false. When you talk about red pens you are talking about both pens and percepts, whether you realise it or not.

That the pen is red just is that it (ordinarily) appears red, and the word “red” in the phrase “appears red” does not refer to a mind-independent property of the pen but to the mental percept that looking at the pen (ordinarily) causes to occur.

I don't care about how Wittgenstein viewed perception and colours. He was not a physicist or a neuroscientist and so he didn't have the appropriate expertise. To think that somehow an examination of language can address such issues is laughable. Do you want to do away with the Large Hadron Collider and simply talk our way into determining how the world works?

You need to get over your obsession with language. The discussion is about perception, not speech. We must look to physics and physiology, not to all the ways that the word “red” is used in English.

I'm sure you will be able to explain your account without sending us off to such a text. — Banno

I don't have an account because I'm not a physicist or neuroscientist. As I have repeatedly said, perception cannot be explained by armchair philosophy.

But of course pain and colour are quite different. — Banno

Only in that they are caused by quite different brain activity.

Tomatoes, strawberries and radishes really have the distinctive property that they do appear to have. They are red. — Banno

You're equivocating.

If we take dispositionalism as an example then "the tomato is red" means "the tomato is disposed to look red". The word "red" in the phrase "looks red" does not prima facie refer to a property of the tomato, and so it does not prima facie follow from "the tomato is disposed to look red" that the tomato has the distinctive property that it appears to have.

So what do you mean by "the tomato is red"? Without further explanation your claim here is a non sequitur.

Try Vision Science – Photons to Phenomenolgy if you want to know more.

Yep. So you have not explained red by equating it with a red percept. — Banno

What are you talking about? Your obsession with language is leading you to nonsense. It's incredibly simple for anyone who isn't blinded by Wittgenstein.

Pain is a percept, red is a percept. That's it. If you don't understand what pain percepts are then read some neuroscience and stab yourself in the foot.

You're asking me which percepts the word "red" refers to. I can only answer such a question by using a word that refers to these percepts, and given that there is no appropriate synonym for "red", all I can do is reuse the word "red".

The word "pain" refers to pain, the word "red" refers to red, the word "sour" refers to sour.

There's nothing "viciously circular" about this.

The red percepts are red, the pain percepts are pain. These questions are tiresome, so if it's all you can resort to then I'm going to end it here.

So which ones are red? Only the red ones? — Banno

This isn't difficult Banno. If you understand what it means for pain to be a percept then you understand what it means for red to be a percept. If you don't understand what it means for pain to be a percept then I can't help you.

There are lots of percepts, many of the same type. Every pain is a percept, every pleasure is a percept, every sour is a percept, every red is a percept.

You want to equate the colour red with a thing you call a red mental percept. But they are not the very same thing. — Banno

Yes they are.

It is very unclear what a 'mental percept" is, when you take it out of the context of the scientific papers that use it. — Banno

And? It's unclear what electrons are when you take them out of the context of the scientific papers that talk about them.

What is rejected is the assertion that red is nothing but a 'mental percept' — Banno

I haven't claimed that. I have only claimed that the red mental percept is our ordinary, everyday understanding of red (even if we do not understand that it is a mental percept).

the science is wrong. — Banno

Well, if you're just going to dismiss the scientific evidence because it disagrees with Wittgenstein's nonsense story about a beetle then we're never going to agree.

I'm going to trust the science, not armchair philosophy, when it comes to explaining how perception works. You do you.

They really have the distinctive property that they appear to. — Banno

The science proves otherwise. They have a surface layer of atoms that reflect various wavelengths of light, but no colour, because colour is something else entirely.

Notice no mental percepts needed — Richard B

Of course they are, else you wouldn't be seeing anything; you'd just have light reaching your eyes and then nothing happening, e.g. blindness or blindsight.

The tomatoes are red. — Banno

The question isn't "are tomatoes red?". The question is "do objects like tomatoes, strawberries and radishes really have the distinctive property that they do appear to have?"

You have admitted before that colour terminology is used in more than one way, and I have agreed. The problem is that you are then using this to equivocate. Any meaning of the word "red" or the sentence "the tomato is red" that does not concern the tomato's appearance is irrelevant. And any meaning of the word "red" or the sentence "the tomato is red" that does concern the tomato's appearance is explained by physics and neuroscience, specifically showing that tomatoes do not have such a property.

Claiming that they do not "really" have these colours is a misunderstanding of the nature of colour. — Banno

No, claiming that they really have these colours is a misunderstanding of the nature of colour.

Vision science: Photons to phenomenology:

People universally believe that objects look colored because they are colored, just as we experience them. The sky looks blue because it is blue, grass looks green because it is green, and blood looks red because it is red. As surprising as it may seem, these beliefs are fundamentally mistaken. Neither objects nor lights are actually “colored” in anything like the way we experience them. Rather, color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights. The colors we see are based on physical properties of objects and lights that cause us to see them as colored, to be sure, but these physical properties are different in important ways from the colors we perceive.

Color:

One of the major problems with color has to do with fitting what we seem to know about colors into what science (not only physics but the science of color vision) tells us about physical bodies and their qualities. It is this problem that historically has led the major physicists who have thought about color, to hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess. Oceans and skies are not blue in the way that we naively think, nor are apples red (nor green). Colors of that kind, it is believed, have no place in the physical account of the world that has developed from the sixteenth century to this century.

Not only does the scientific mainstream tradition conflict with the common-sense understanding of color in this way, but as well, the scientific tradition contains a very counter-intuitive conception of color. There is, to illustrate, the celebrated remark by David Hume:

"Sounds, colors, heat and cold, according to modern philosophy are not qualities in objects, but perceptions in the mind." (Hume 1738: Bk III, part I, Sect. 1 [1911: 177]; Bk I, IV, IV [1911: 216])

Physicists who have subscribed to this doctrine include the luminaries: Galileo, Boyle, Descartes, Newton, Thomas Young, Maxwell and Hermann von Helmholtz. Maxwell, for example, wrote:

"It seems almost a truism to say that color is a sensation; and yet Young, by honestly recognizing this elementary truth, established the first consistent theory of color." (Maxwell 1871: 13 [1970: 75])

This combination of eliminativism—the view that physical objects do not have colors, at least in a crucial sense—and subjectivism—the view that color is a subjective quality—is not merely of historical interest. It is held by many contemporary experts and authorities on color, e.g., Zeki 1983, Land 1983, and Kuehni 1997.

Neural representations of perceptual color experience in the human ventral visual pathway:

There is no color in light. Color is in the perceiver, not the physical stimulus. This distinction is critical for understanding neural representations, which must transition from a representation of a physical retinal image to a mental construct for what we see. Here, we dissociated the physical stimulus from the color seen by using an approach that causes changes in color without altering the light stimulus. We found a transition from a neural representation for retinal light stimulation, in early stages of the visual pathway (V1 and V2), to a representation corresponding to the color experienced at higher levels (V4 and VO1).

Opticks:

The homogeneal Light and Rays which appear red, or rather make Objects appear so, I call Rubrifick or Red-making; those which make Objects appear yellow, green, blue, and violet, I call Yellow-making, Green-making, Blue-making, Violet-making, and so of the rest. And if at any time I speak of Light and Rays as coloured or endued with Colours, I would be understood to speak not philosophically and properly, but grossly, and accordingly to such Conceptions as vulgar People in seeing all these Experiments would be apt to frame. For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour.

You are taking the special case in which for the purposes of experiment researchers restrict "seeing red" to having a "mental percept of red" and taking this to be what "seeing red' is in every other case. — Banno

I'm not. I'm saying that our everyday, ordinary conception of colours is that of sui generis, simple, qualitative, sensuous, intrinsic, irreducible properties, not micro-structural properties or reflectances, and that these sui generis properties are not mind-independent properties of tomatoes, as the naive colour realist believes, but mental percepts caused by neural activity in the brain, much like smells and tastes and pain.

The relevant question "do objects like tomatoes, strawberries and radishes really have the distinctive property that they do appear to have?" is not answered by engaging in a linguistic analysis of all the ways that the word "red" or the phrase “seeing red” are used, and so your continued insistent to appeal to language is a fundamentally flawed approach to the problem. The only people who can answer the question are physicists and neuroscientists. Armchair philosophy is useless in this situation.

You're contradicting yourself at nearly every turn, in addition to the fact that your 'argument' leads to the absurdity of you claiming out loud, for everyone to see, that you do not conclude anything about stimulus from your experience all the while insisting that there is no color in stimulus. — creativesoul

I'm reporting what the science says.

Opticks:

The homogeneal Light and Rays which appear red, or rather make Objects appear so, I call Rubrifick or Red-making; those which make Objects appear yellow, green, blue, and violet, I call Yellow-making, Green-making, Blue-making, Violet-making, and so of the rest. And if at any time I speak of Light and Rays as coloured or endued with Colours, I would be understood to speak not philosophically and properly, but grossly, and accordingly to such Conceptions as vulgar People in seeing all these Experiments would be apt to frame. For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour.

Neural representations of perceptual color experience in the human ventral visual pathway:

There is no color in light. Color is in the perceiver, not the physical stimulus. This distinction is critical for understanding neural representations, which must transition from a representation of a physical retinal image to a mental construct for what we see. Here, we dissociated the physical stimulus from the color seen by using an approach that causes changes in color without altering the light stimulus. We found a transition from a neural representation for retinal light stimulation, in early stages of the visual pathway (V1 and V2), to a representation corresponding to the color experienced at higher levels (V4 and VO1).

Vision science: Photons to phenomenology:

People universally believe that objects look colored because they are colored, just as we experience them. The sky looks blue because it is blue, grass looks green because it is green, and blood looks red because it is red. As surprising as it may seem, these beliefs are fundamentally mistaken. Neither objects nor lights are actually “colored” in anything like the way we experience them. Rather, color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights. The colors we see are based on physical properties of objects and lights that cause us to see them as colored, to be sure, but these physical properties are different in important ways from the colors we perceive.

Color:

One of the major problems with color has to do with fitting what we seem to know about colors into what science (not only physics but the science of color vision) tells us about physical bodies and their qualities. It is this problem that historically has led the major physicists who have thought about color, to hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess. Oceans and skies are not blue in the way that we naively think, nor are apples red (nor green). Colors of that kind, it is believed, have no place in the physical account of the world that has developed from the sixteenth century to this century.

Not only does the scientific mainstream tradition conflict with the common-sense understanding of color in this way, but as well, the scientific tradition contains a very counter-intuitive conception of color. There is, to illustrate, the celebrated remark by David Hume:

"Sounds, colors, heat and cold, according to modern philosophy are not qualities in objects, but perceptions in the mind." (Hume 1738: Bk III, part I, Sect. 1 [1911: 177]; Bk I, IV, IV [1911: 216])

Physicists who have subscribed to this doctrine include the luminaries: Galileo, Boyle, Descartes, Newton, Thomas Young, Maxwell and Hermann von Helmholtz. Maxwell, for example, wrote:

"It seems almost a truism to say that color is a sensation; and yet Young, by honestly recognizing this elementary truth, established the first consistent theory of color." (Maxwell 1871: 13 [1970: 75])

This combination of eliminativism—the view that physical objects do not have colors, at least in a crucial sense—and subjectivism—the view that color is a subjective quality—is not merely of historical interest. It is held by many contemporary experts and authorities on color, e.g., Zeki 1983, Land 1983, and Kuehni 1997.

And yet... you and Michael are doing exactly that. — creativesoul

I'm not concluding anything from my experience. I am telling you what physics and neuroscience have determined. I accept what the scientists say about the way the world works, not what some armchair philosopher says.

Are there colorless rainbows? — creativesoul

I responded to this above. If Newton doesn't answer the question then you need to clarify what you mean by it.

Are you saying that there are colorless rainbows? — creativesoul

It's not clear what you mean by the question, but I'll quote Newton's Opticks:

The homogeneal Light and Rays which appear red, or rather make Objects appear so, I call Rubrifick or Red-making; those which make Objects appear yellow, green, blue, and violet, I call Yellow-making, Green-making, Blue-making, Violet-making, and so of the rest. And if at any time I speak of Light and Rays as coloured or endued with Colours, I would be understood to speak not philosophically and properly, but grossly, and accordingly to such Conceptions as vulgar People in seeing all these Experiments would be apt to frame. For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour.

Rainbows look coloured because the various wavelengths of light cause various neurological activity in the visual cortex producing various colour percepts. This is the scientific fact.

Colors are unlike chemicals. — creativesoul

Correct, they are like tastes. They are mental percepts caused by neurological activity, often in response to sensory stimulation.

The light without color?

Earlier you forwarded the claim "there is no color in light". The visible spectrum is light. If there is no color in light, and the visible spectrum is light, then it only follows that there is no color in the visible spectrum.

Yet you offer a rainbow called the visible spectrum.

Colorless rainbows. — creativesoul

Light is just electromagnetic radiation, which is the synchronized oscillations of electric and magnetic fields. Colour is not a property of these fields. When it stimulates the eyes this causes neurological activity in the visual cortex, producing colour percepts. Just like chemicals stimulating the tongue cause neurological activity in the gustatory cortex, producing taste percepts. Colours are no more "in" light than tastes are "in" sugar.

Your naive projection has long since been refuted by physics and neuroscience.

There is no problem. The self-referential sentence "this sentence contains five words" is both meaningful and true. The self-referential sentence "this sentence contains fifty words" is both meaningful and false. It's that simple.