I'm talking about the color that is inside our heads. I'm not talking about wavelengths.

It seems like any attempt to answer the question 'What is color?' or 'How does brain create color?' must involve referring to 'color' itself.

We've assumed in mainstream science that 'color' must be getting produced in our brain by some complex physical process, and yet we have no clue what that physical process is, or how that process achieves the phenomenon of 'vision'.

Any attempt to explain the origin of color using fundamental ideas like 'forces', 'space', 'charge', 'mass', 'time', etc, is paradoxical. Any complex phenomenon which is explained using those ideas is described by 'movement of particles' or 'flow of energy'. We can explain the phenomenon of planet formation using those ideas (because planet formation involves movement of particles or flow of energy wrt time).

But it's easy to see that 'color' is not one such phenomenon. When we question 'How color gets produced?', we're not asking why some particles move in the way they do. This question is not about movement at all.

In the end, asking 'What is vision?' seems just as complicated as like asking 'What is time?' or 'What is mass?'. These are the things which just are. Physics is about exploring the properties of these fundamental things instead of asking why these things exist.

So I'm saying that solving the mystery of color should involve advancing our understanding of fundamentals of Physics itself. I'm surprised that this is not the popular take on this question, because the phenomenon of 'color' is fundamentally different from any other phenomenon we've explained using the standard models of Physics.

  • 2
    Why ? See Evolution of human colour vision. It is quite debatable that we cannot understand whatb the perception of colour is... Commented May 27, 2020 at 12:08
  • @MauroALLGERANZA I'm not sure how anyone could describe even a primitive form of vision without referring to some kind of mental picture. And that's completely circular because there's no definition of pictures without defining vision first.
    – Ryder Rude
    Commented May 27, 2020 at 12:10
  • @MauroALLEGRANZA The only form of primitive vision we could describe without referring to pictures is where eye receives light and body reacts according to some instructions. But that kind of vision does not involve any concept of color.
    – Ryder Rude
    Commented May 27, 2020 at 12:14
  • 3
    I'm not convinced about the "fundamental": we can imagine B/W vision; many mammals do not see three fundamental colors. This means that the universe is colorless (mass and energy it is enough) and we perceive colors due to the contingent way our eye has evolved. We can understand (more or less) the physical process and the evolution one. There is still a "deep reason" behind that ? Maybe... maybe not. Commented May 27, 2020 at 12:20
  • "Any attempt to explain the origin of color" ...but there are subjective facts about color; plenty of them. Yellow is brighter than blue, green is cool, orange is closer to red than it is to green, and so on. There's at least room for an explanation of color to align with such subjective facts.
    – H Walters
    Commented May 27, 2020 at 12:21

3 Answers 3


We have scientific understanding of a lot that is relevant to color perception, not only wavelengths but also of photoreceptors, how they relate to color blindness, etc. But the subjective experience of color perception is perhaps the most common example used when talking about qualia, the what it is like of an experience. There are various arguments as for why qualia would be non-physical, such as one based on the inverted spectrum scenario, which indeed is also about color.


There is a lot of philosophy out there about colour perception. It's a big topic. So I will limit myself to a few remarks.

I would follow The Private Language Argument, to say the 'qualia' of colour is essentially meaningless, what matters is the accurate use of linguistic tokens, for generating the mappings behaviour is based on. The source of what you call paradox, is assuming that colour is a single 'kind of thing', when it is really a shortcut for a whole range of narrative groupings - wavelengths, sensations, internal experiences, labels, linguistic tokens.

Consider this account of someone with proven tetrachromatism, so who experiences 4 primary colours. She describes her experiences before she was diagnosed as having minimal discrepancies. The same genes can result in 2-cone colour-blindness, and there more discrepancies of mapping are seen - it prevents people qualifying as electricians in the UK, or being on the frontline in the fire service. But the inner difference of experience is rarely discussed, or even noticed.

The idea of colour as purely objective is challenged by impossible colours, and a range of optical illusions show us how much post-processing is done - we can deduce through modelling that this is something like a convolutional neural network, identifying image properties like edges, shade, orientation, volume, and textures, with progressive processing and converging towards a consilient cognitive model. The hyperbolic headline of that may be 'your brain hallucinates your conscious reality', but as Anil Seth here makes clear that is in the context of closely-argued well-evidenced thinking about perception. Even Donald Hoffman's work on why we cannot rely on evolution to give us accurate perceptions accepts that tools like reasoning and consilience can lead us to more accurate cognitive models, even with unreliable inputs.

"our understanding of fundamentals of Physics itself"

It sounds like you have decided to implicitly assume noumena for phenomena, that you think we can access the thing-in-itself of reality. I think that's misguided, and that the conservation of information in physics converges with the Buddhist idea of no-essences/sunyata, to suggest nothing is ever truly seperate, including observer and observed, noumena and phenomena, ontic and epistemic.

  • I know that perception of the color of an object is not unique. But what IS color? What IS vision? The best we can manage so far is hand-wavy or circular answers to these questions. And it's easy to see why. The very nature of this question prohibits any explanation in terms of other fundamental physical phenomena. And that's because vision is fundamental itself. You can say that vision is the brain's best model to make itself understand outside world. But that statement barely comes even infinitesimally close to actually describing what that model is.
    – Ryder Rude
    Commented May 28, 2020 at 14:37
  • @RyderRude: No. Consider how much of the world doesn't distinguish between blue & green, & are less good at picking out tones. The converse applies where there are more words, and a society practices distinguishing. "vision is fundamental itself" In Buddhism they have en.m.wikipedia.org/wiki/%C4%80yatana Mind-spaces occur from feedback between senses & phenomena. I can only guess you are doing the 'qualia are magic' thing, but there is a mind-space expansion using language.
    – CriglCragl
    Commented May 30, 2020 at 12:11
  • I am not saying that qualia are magic or metaphysical. Magic is just undiscovered physics after all. It's just that vision is a fundamentally different kind of phenomenon than what standard physical models are designed to explain. Modern Physics laws are limited to explaining the processes which involve the changes in configuration of particles distributed in space over time. Vision is not one such thing. Can you define vision without referring to vision itself?
    – Ryder Rude
    Commented May 30, 2020 at 12:43
  • The best we can do is saying 'vision is a model' or 'vision is a feedback'. Well then 'hearing' is also a model or feedback. Can we describe what distinguishes the models using language?
    – Ryder Rude
    Commented May 30, 2020 at 12:55
  • @RyderRude: I really don't understand your points. Everything is inside our heads, where we build a salience landscape, highlighting relevant features, allowing us to act effectively. There isn't one definition of colour, or vision, because they are bundles of related phenomena. What is mass led to the Higgs boson. What is time is key to developing quantum gravity.
    – CriglCragl
    Commented May 30, 2020 at 15:06

Indeed, there's a whole history regarding just this question: suppose Mary is a colorblind scientist who knows all the dynamical facts about color. One day, her colorblindness goes away and she finally sees a red apple as red. If intrinsic color facts are elemental, it seems she gains knowledge at this time. On the other hand, this "seeming" requires some atomization of "items of knowledge" such that awareness of qualia can be an individual such item (a counterargument being: in an ethereal way Mary now "knows more" but this kind of "knowledge" is trivial or weak or what).


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .