Sounds like she is describing imaginary or impossible colors.
Image search "color illusion": https://duckduckgo.com/?q=optical+color+illusion&t=ffab&atb=...
Or see (literally) "Benham's top" where a black-and-white pattern on a spinning disk induces the perception of color. https://en.wikipedia.org/wiki/Benham%27s_top
I see slightly different colors out of each eye, with no way of knowing which eye is correct.
Neither eye is correct: color is subjective.
"Who is the master who makes the grass green?"
It's a deep question.
With psychedelics, I saw colors that I'd never seen in reality. But that's just color illusion on steroids.
What interesting, though, is that I saw patterns in objects that normally seemed ~uniform in color. So maybe "software tweaks" can mitigate hardware limitations.
It seems to me that when everything looks the same from birth on (excepting perhaps focus. ;) ) then it is difficult to compare what one sees with what others see.
I also wonder if some colored LEDs tend to be "worst case" as they may be monochromatic and if the eye is not sensitive to that particular wavelength, it will not be visible as color.
Actually... I also wonder about how a wide gamut of colors can be represented by relative intensity of three primary colors: red, green and blue. I would expect the emitters in, for example, an LCD screen to emit light at specific frequencies. How can any combination of three frequencies represent what must be a broad rage of frequencies that form any given color in the world around us.
How colorblind you are -- or maybe in what way -- determines which color combinations you can distinguish characters for. That's horrible, I know, but I'm tired.
I suppose it depends on what mutation(s) you carry. And probably other factors that affect penetrance.
So "somewhat" was the diagnosis, not my experience.
But I have known other red/green colorblind people. And I can distinguish reddish vs greenish colors better than some. But worse than others.
http://www.dict.org/bin/Dict?Form=Dict2&Database=*&Query=col...
Freedict gives:
That aspect of things that is caused by differing qualities of the light reflected or emitted by them, definable in terms of the observer or of the light
https://www.thefreedictionary.com/color
That is, colour is a perception, dependent on the observer. Agreed-on colours being those on which typical observers share common experience, is correct.
Wavelengths, pigmentation, and diffraction effects (which give rise to colour in observers) are phenomena.
The terms quale and qualia suggested by @codebolt are indeed quite useful.
(Language itself is shared agreement among symbolic references, given context.)
Tetrachromats could plausibly see more nonspectral colors by activating their extra color receptor and one of the other ones. There would be no exact equivalent in trichromatic vision.
It depends on what their brains decide to do with it- maybe they would just land on an existing color in between. But there's no reason it has to.
So these colors are something that tetrachromats could maybe see while awake, but usually with lots of other colors mixed in. Asleep, maybe the brain starts to play with them and generates pure versions of them. Trichromats wouldn't be very likely to have these dreams because their brains don't have experience of tetrachromat nonspectral colors at all.
I imagine in school the teacher tells the poor girl: Mix the blue and yellow colors to get green, and the girl doesn't understand because she has a lot more complex color model than the teacher.
We see magenta as a separate color because we can distinguish it from green- it's not green, because Red and Blue don't activate our green cones. But we can't distinguish between spectral yellow and R+G because there's no yellow cone: the activations of all our cones are more or less identical in both cases.
If you have a yellow cone, you'd conceivably be able to distinguish between both kinds of yellow: redgreen and yellow could look as different as green and redblue do. I'm not sure how that would look as a "wheel", perhaps a figure-eight with the crossing at yellow.
Whereas a hypothetical tetrachromat with an additional cone type that activates to the yellow wavelength, will have obviously different activations of their cones for the "wavelength of yellow" and "wavelengths of red and green mixed". And hence experience them as different colors.
I'm not familiar enough with the different definitions of color spaces to define how to model this. You could easily define it as a four-dimensional RGBY color space, but to my understanding the other color spaces are defined because they have better properties for combining different colors, or playing better with interpolation between colors.
It would be a challenge to come up with a good four-dimensional color space that is a useful artistic and visual tool, given that there are very few people around to evaluate it! And also because all computer monitors are trichromatic, so it'd be a job in itself to set up a test system.
I wish someone in the interview had asked some of these people how they experience photos on computers!
Tetrachromatic colors could be placed in a tetrahedron, defining a space and being approximated as a sphere. A perceptually uniform representation would probably be curved on the three edges that agree with the spectrum and flat on the three that don't. Green is still probably the biggest. Then you'd add luminance as a fourth dimension because it's still rods.
With tetrachromats we get a four-dimensional space of color. So we need something like RGBX or a two-dimensional hue value like for example H1,H2,S,V. That's what I meant with a second hue circle orthogonal to the one we already know.
What we see as yellow is for the tetrachromat a whole second hue circle varying in the value of second hue.
An example: Yellow is a point on the first hue circle. For the tetrachromat these colors are different, but boring yellow for us:
- pure yellow
- mixture of red and green
- mixture of pure yellow, red and green
In other words, what we see as yellow is a whole dimension of different colors for tetrachromats.
Also, if you mix R+B, that's magenta, and if you start mixing in blue it will turn white or gray. But if you can see yellow, RYB would look different from R+a little g+B, which is what RYB would look for trichromats, I think.
This is honestly one of the saddest parts of human society. Some people, including those in positions of authority, either don't understand or outright reject the notion that different people perceive the world differently.
In secondary school I argued along the lines you describe, that you can mix three colours in a circle, and then a fourth around the circumference mixes only with at most two of the others - and in terms of the FCT is then a 'barrier' allowing re-use of the first three.
That's quite off-topic, but you suddenly jolted my memory of it. More on-topic, being colour-blind (never told which type and I can't work it out either) I find conversations about colours frustrating, and very strange to wonder if we see anything alike at all, or just learn to call the same physical thing alike despite perceiving it perhaps very differently.
Proving some maps can't be colored with three colors is easy, you only need to find one and enumerate all the three-colorings and find none of them work.
It's not really a theorem about colors though, they're just labels.
Re proving any, I replied to a sibling comment. What I was imagining was the inverse - proving that you can't construct one that requires a fifth.
I recognize that this comment includes jargon, but I assume you'll Google it. I'd include diagrams but HN doesn't support them.
But, I understand and trust the mapping of the problem to a graph, so perhaps if I see why the problem is hard on a graph that should be enough for me.
But my reasoning was along the lines (but now in my newfound terminology) of:
K1 - trivially 1 colour needed. K2 - 2.
If we add another region on the map, we either have K3 or K1,2. In the latter case the third region/vertex need only be different to the one it touches, but K3 clearly needs 3 colours.
Adding the fourth region is similar, and again K4 clearly needs 4.
The fifth region touches at most 3 others, since K5 is non-planar. Thus, it can take the colour of the untouched region.
That's not very formal, but why isn't proof by induction easy from there? i.e. if we can't build a map that ever requires a fifth colour, then it can't be that there exists a map which requires more than four?
* It's easy starting from the end, just put one colour in the middle, then alternate second/third colours around the edge until you get back to the start and have to add a fourth. From construction, the worst case is from K1,2 then adding another for K1,3 at which point we need four colours already, but when we add two more on what will be the C5# around they each only connect to one each side and the center. In adding each one you can simply use the colour one hop over on the circumference.
# Since the center of K1,3 must be the center of the final C5-plus-thing, as it already had 3 spokes.
It's just that the C₅-plus-thing requires four colors, even though it doesn't contain any K₄ induced subgraphs. So we could imagine that there might be some larger planar graph that requires 5 colors without containing K₅. As it turns out, there isn't, but that's the thing that's hard to prove.
You could put them in front of light source that generated pure wavelengths designed to selectively activate their extra cone and ask what they see when you start mixing pure blue or green into it. Maybe they'd recognize those colors from their dreams, maybe not. I don't know. But it's a mechanism that would explain how tetrachromats might dream colors that trichromats don't.
We don't see bright, "pure" magenta very much, and when we do it's usually because we've engineered it. Nobody is engineering pigments for tetrachromats to enjoy.
If I'm right, people who are nearly (but not entirely) colorblind (anomalous trichromats) due to a shifted cone would likewise be able to dream in colors they are capable of seeing only dimly while awake, whereas dichromats wouldn't.
The trick to impossible colors is recognizing that our existing receptor spectra overlap. It's not possible to get "100% red" in the sense of only the "red" cone cells firing and none of the "blue" or "green" ones, because those other cells are going to fire at some small rate for the same frequencies.
But our brain can certainly receive such a color even if our eyes don't produce it, so in some sense we "understand" it as a color even if we'll never see it outside a laboratory or hallucination.
There are separately colors which we are wired to hypothetically receive, as you point out (and I find interesting) - IE, if you replace the eye with some sort of artificial replacement, then such a signal could get received by the brain, but with the current sensors it is impossible (also, I suppose a colorblind person could receive such a signal as 100% red without the other colors).
There's also the possibility during a dream of creating objects or sensations that are not physically possible. For instance, I've had dreams where I had a form of telekinesis, and obviously there's no sort of brain wiring to manipulate physical objects outside of the normal motor functions. Still, it made sense in the dream - and it's not like I could describe how I did it, and it's not because the hardware exists but the sensor doesn't.
Although - you could argue that there's a layer of abstraction in the brain of such things in the brain - for instance, when I'm typing these words I don't actually ever have any conscious awareness of my finger motions. I don't even think about the act of typing at all; only the words. So, thinking about it, the brain does have an idea of manipulating objects outside of a need for muscles to do it.
I would think for a tetrachromat the abstract sensation of seeing colors you can't describe to others is itself a familiar one, and that feeling itself is something you might encounter in dreams. My dreams tend to start with a feeling, and then build a context for it.
Tl;dr - dreams are weird.
Strange to think there are people who can perceive two orders of magnitude more colour than me. Damn.
Think something like an RGB lamp but with more colors/wavelengths, and adapted to her particular spectral response.
Having built a similar kind of lamp myself, I have to say it was quite wild even for a boring old trichromat as me!
Maybe those colours are what I would see if I had properly functioning cones, or even a fourth cone variant. Or maybe they're just a symptom of wider brain dysfunction due to the psychedelic drugs. Hard to know...
It makes me fairly proficient at driving, dodging moving obstacles while doing any physical activiy, and fast-paced games (like FPS) - even if the trade off is that I occasionally killed teammates because I couldn't see the color differences between players at times.
Everything has it's pros and cones (pun :D)
This type of pattern matching is frequently how I go about navigating the world.
Of course I envy her, but I mostly just happy that she can experience some aspects of our world better than most other people. It's like with talents: the fact that someone has a particular talent or skill that you lack doesn't make you hate this person. Instead you ask them to show it off, they do, you "Oo-ooh!" and "Aa-aah!", they feel really good about themselves and you're both happy.
Sometimes she is sad I can't appreciate something she sees, but we don't dwell on it. She would often describe the shape or a pattern she sees and I try to picture it and say something like "Oh that's neat!".
Also, there are some clothing items I never combine, and I always ask her for advice when I select my cloths, or colors for my presentation or charts.
Colors are very cool. I wish we could have some kind of tech that would allow us to see colors like some birds or aquatic species do. These days there are glasses for colorblind people to give them some extended color perception, so the tech is making some baby steps.
It turns out that many color-blind people have the normal distribution of cones, but the spectral response is similar enough that the brain can't differentiate. By putting an optical notch filter in the overlap region, the difference is accentuated and the brain starts picking it up normally.
You can practice by surrounding yourself with people better than you. Play games with people better than you. Find mentors.
Grow as a person so you love yourself rather than envy others. Recognize that almost everyone has something you don't. Better than you at something.
Reflect on the great things about yourself. Remember who you are. Where you started.
Be good. Be true to yourself. Develop your moral code. Treat all with respect and love. Including you with all your imperfections.
But by 2010, [Jordan] had found a subject who perfectly acted the part of a tetrachromat. Jordan’s “acid test” involved coloured discs showing different mixtures of pigment, such as a green made of yellow and blue. The mixtures were too subtle for most people to notice: almost all people would see the same shade of olive green, but each combination should give out a subtly different spectrum of light that would be perceptible to someone with a fourth cone. Sure enough, Jordan’s subject was able to differentiate between the different mixtures each time. “When you ask them to discriminate between the two mixtures, a tetrachromat can do it very quickly. They don’t hesitate,” says Jordan.
Science has a method for cutting through speculation - in this case, it is a variant of the Ishihara test.
I'd use a 2-panel diagram. On each round, the panels are assigned random colors. The subject is asked "are the panels same, or different?" Some proportion of the time, they're identical. If they just mash "different" every time, you'll see that in the data and you'd reject those subjects -- or accumulate those false guesses into an uncertainty measure. If they hit 'same' on different colors... make a graph with edges between those colors. Some time after the graph is connected, try and find a minimum vertex cover. The order if that vertex cover should be a reasonable estimate of the number of colors a person can see.
She also sometimes see colors in her dreams that are outside of a pallet humans see in real life, but after she wakes up she can't describe them. It's not one color or one hue, there are several colors that she can only experience in her dreams.