[HN Gopher] New colors without shooting lasers into your eyes
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New colors without shooting lasers into your eyes
Author : zdw
Score : 161 points
Date : 2025-07-17 16:01 UTC (3 days ago)
(HTM) web link (dynomight.net)
(TXT) w3m dump (dynomight.net)
| kadoban wrote:
| I am curious how these work for people with common kinds of
| colorblindness. The author mentions at the end that they likely
| don't work for that case, but they don't seem to have spent much
| time thinking about it.
|
| Would it be possible to generate ones that _would_ work for
| specific kinds of colorblindness? Or is the entire concept doomed
| due to the specific way(s) that colorblind eyes are messed up?
| kookamamie wrote:
| The animation worked for me, I'm red-green colorblind.
| qayxc wrote:
| The red inside, reddish-orange outside was a little strange -
| I'm not colour blind, but have a really hard time
| distinguishing shades. As soon as I focused on the white dot,
| the red circle started to blend with the background and
| disappeared completely (was just one single colour for me).
| Only when it started shrinking did I hallucinated a faint green
| aura around it until it was gone.
| dentemple wrote:
| I have deuteranomaly, and the hallucination worked for me, and
| it did appear like a crazy saturated blue-green ring around the
| shrinking red circle.
|
| I suspect, however, that those of us with deuteranomaly
| probably see a different blue-green than normal-sighted folks
| due to the bent color cones.
|
| The real question is, what about the folks with Deuteranopia
| (no working green cones at all)?
|
| Deuteranomaly, though, is still probably the best place to
| start since that's the big one that affects (some say) up to
| 10% of all males. Every other form of colorblindness affects a
| much slimmer percentage of the population.
| tricolon wrote:
| I have red-green weakness but only saw a lighter green around
| the circle as it became smaller.
| osamagirl69 wrote:
| It is incredible to see a concept going from 'optical table of
| sensitive equipment fraught with numerous safety concerns' to
| 'here is a 1 kB svg animation, stare at it for 1 minute' in 3
| months.
|
| Enjoy your forbidden color, you earned it!
| layer8 wrote:
| The article however concludes: "So do the illusions actually
| take you outside the natural human color gamut? Unfortunately,
| I'm not sure. I can't find much quantitative information about
| how much your cones are saturated when you stare at red
| circles. My best guess is no, or perhaps just a little."
| armchairhacker wrote:
| This is really cool. Tangentially, it's an example of an
| important life lesson, "work smarter not harder". To see the
| impossible color, you could build a super-expensive, super-
| complicated laser to directly stimulate the exact cells; or you
| could desensitize the other ones with an optical illusion that
| works on a personal device (effectively zero cost and minimal
| complexity since it uses existing technology).
|
| Not to say the laser is a waste, despite the above I'd argue it's
| very useful. It lets us test how effectively the above actually
| works, and has other applications.
| do_not_redeem wrote:
| This optical illusion isn't some brand new thing. It's been
| widely known since I was a child, and surely hundreds of years
| before that.
|
| The laser system results in a stronger perceptual effect than
| you get from the illusion alone. We didn't have the technology
| to build it until recently. I'm certain the people who built it
| knew about the illusion, and it's probably what inspired the
| experiment in the first place.
| fortyseven wrote:
| That is a notion that is far easier to make in hindsight.
| gcr wrote:
| What is the animation supposed to be like? I see just a black bar
| on the left narrowing, but nothing else happens. The red circle
| and green background and white dot didn't change. (iOS 26 beta,
| iPhone 15)
| satellite2 wrote:
| After the black bar finish narrowing the red circle gets
| smaller slowly
| gpderetta wrote:
| After the black bar disappears, the circle start shrinking and
| on the boundary you can indeed an intense azure/green
| colour.for me quickly flickering the eyes left and right did
| temporarily increase the patches of intense colour.
| solardev wrote:
| It's not the animation itself that does anything magical, but
| the afterimage (I think that's what you would call it?) your
| eye produces after you stare at the dot for long enough. The
| black bar is just a countdown timer for the impatient.
|
| But try to maintain laser focus on the central dot, not letting
| your eyes move or blink if you can help it. Once the black bar
| depletes, the circle should start shrinking, and around its
| periphery (like an eclipse) should be some incredibly vivid,
| super saturated colors.
| fabiospampinato wrote:
| Now we need to know from the people that experienced the laser
| how different this hallucination feels compared to that. Very
| cool stuff!
| sampl3username wrote:
| Using psychedelics, specifically 2C-B and LSD, you can also see
| very saturated colors you don't normally see in daily life. I see
| very saturated magentas.
| louthy wrote:
| I wonder how much of this is 'seeing' and how much is emergent
| in the brain due to the drug. I suspect the latter, but that's
| just opinion.
| dr_dshiv wrote:
| "how much of this is 'seeing' and how much is emergent in the
| brain"
|
| Yeah... it's gonna be hard to distinguish those in the best
| of circumstances.
| sampl3username wrote:
| Seeing is also an illusion by the brain, all colors are in
| your head.
| louthy wrote:
| I realise that, I'm just speculating on _when_ the effect
| emerges. Whether it's because of changes in the cones
| (which are the tips of nuerons) or a later emergent
| property.
| GuB-42 wrote:
| Most likely an emergent property. Psychedelics affect
| serotonin pathways, I don't think that cone cells and the
| first layers of neurons behind them have serotonin
| receptors.
| neom wrote:
| Everything is quite intense that way with 2C-B, very very rich,
| but in a more psilocybin way than LSD. 2C-B is super weird, I
| find it hard to pinpoint what it is about 2C-B that is so
| unique among the phenethylamines/tryptamines.
| _Microft wrote:
| Open the experiment animation and refresh the page multiple times
| to refresh the countdown while looking at the white pixel (from
| the same point of view) to get an even more impressive effect.
| TheAceOfHearts wrote:
| To me it looked like the circle outline had a shimmering aura, it
| felt very magical. This was a incredibly delightful experience so
| I just want to say thanks for posting it.
|
| When the circle was around the halfway point of shrinking the
| color looked the most vivid for me, so be sure to wait the whole
| duration.
| bozhark wrote:
| Similar, an extremely bright and magnificent teal-ish green
| with a vibrant yellow edge was dancing around the edge of the
| circle
| soared wrote:
| You can also look at the background about halfway through and
| get a large circle of the new color, the same size as the
| original circle.
| tanepiper wrote:
| Interesting colours coming out of it - a while back I suspected I
| have https://en.m.wikipedia.org/wiki/Tetrachromacy since I was
| able to describe colours more vividly that others, and certain
| plants for me like Verbena have a glow around them.
| Aardwolf wrote:
| I'd love it if there was someone with tetrachromacy who also
| knows a bit about color theory and perception and can talk
| about it!
|
| How do you describe the experience scientifically? Do you get a
| whole bunch of extra colors you'd want to give a distinct name
| since they're so clearly different from the standard
| trichromatic colors?
|
| Is a computer screen annoying because it can only produce a
| subset of the colors you can see?
|
| Do you notice that you have a fourth parameter or dimension in
| the colors you see, so would want a 4th component in RGB, HSV,
| etc... color sliders? E.g. for our HSL, would the fourth
| parameter be hue-like, saturation-like, lightness like or some
| completely novel other thing? If hue like, do the hues also
| form a 2D sphere or torus like topology similar to how our
| trichromatic hue forms a circle?
|
| I'd expect at least twice or 3x as many named colors, since for
| every regular color (red, green, blue, yellow, orange, purple,
| pink, grey, brown, black, white, ...) , you'd have a fourth
| dimension altering it that can be low, medium or high in value
| ...
|
| E.g. for our yellow, you'd have yellow with not the extra
| signal, a bit of the extra signal or lots of the extra signal.
| Is this the case or not? Perhaps the overlapping reduces it,
| but as said in the article trichromats also have overlap yet we
| definitely see a lot more distinct colors than dichromats.
| dr_dshiv wrote:
| You can ask this lady: https://concettaantico.com/
| dr_dshiv wrote:
| Some people with two X chromosomes have this ability. And all
| birds.
|
| If you are bored, try to get Gemini/claude to make a color
| wheel for birds or tetrachromats.
|
| An aside: Recently I learned that birds are reptiles. That hurt
| my brain and I'm still recovering. Especially since the modern
| dinosaur exhibit claiming this fact contradicted the 1980s era
| reptiles exhibit down the hall (both at the British museum).
| nvch wrote:
| It's enough to stare at anything for a few minutes without moving
| eyes to get similar effects and hallucinations.
|
| We see with good resolution only a small part of our visual
| field. Perhaps the brain starts to "invent" what's there it we
| don't give it information by constantly moving eyes.
|
| As a more advanced version, they say that fire kasina practice
| may produce very interesting visual effects.
| juliushuijnk wrote:
| To get 'speed up' the effect, move your face close (to the red)
| then away from your screen.
| georgecmu wrote:
| _For whatever reason, evolution decided those wavelengths should
| be overlapping. For example, M cones are most sensitive to 535 nm
| light, while L cones are most sensitive to 560 nm light. But M
| cones are still stimulated quite a lot by 560 nm light--around
| 80% of maximum._
|
| The reason is simple: genes coding the long wave opsins (light-
| sensitive proteins) in these cones have diverged from copies of
| the same original gene. The evolution of this is very
| interesting.
|
| Mammals in general have only two types of cones: presumably they
| lost full color vision in the age of dinosaurs since they were
| primarily small nocturnal animals or lived in habitats with very
| limited light (subterranean, piles of leaves, etc.) Primates are
| the notable exception, and have evolved the third type of cone,
| enabling trichromatic color vision, as a result of their
| fruitarian specialization and co-evolution with the tropical
| fruit trees (same as birds, actually).
|
| So, what's interesting is that New World and Old World primates
| evolved this cone independently. In Old World primates the third
| cone resulted from a gene duplication event on the X chromosome,
| giving rise to two distinct (but pretty similar) opsin genes,
| with sensitivity peaks at very close wavelengths. As a note,
| because these genes sit on the X chromosome, colorblindness
| (defects in one or both of these genes) is much more likely to
| happen in males.
|
| New World primates have a single polymorphic opsin gene on the X
| chromosome, with different alleles coding for different
| sensitivities. So, only some (heterozygous) females in these
| species typically have full trichromatic vision, while males and
| the unlucky homozygous females remain dichromatic.
|
| Decent wikipedia article on the subject:
| https://en.wikipedia.org/wiki/Evolution_of_color_vision_in_p...
|
| Types of opsins in vertebrates:
| https://en.wikipedia.org/wiki/Vertebrate_visual_opsin
| im3w1l wrote:
| > So, only some (heterozygous) females in these species
| typically have full trichromatic vision
|
| Wow that's wild how heterozygousity can be that helpful. Makes
| you wonder if there are other genes like that.
| rozab wrote:
| Some human females have functional tetrochromatic vision.
|
| https://jov.arvojournals.org/article.aspx?articleid=2191517
| im3w1l wrote:
| No I meant like if there is some other gene where the two
| different variants are synergistic to each other.
| andyfilms1 wrote:
| This is a good biological explanation. The physical explanation
| is, if the sensitivities didn't overlap, our spectral
| sensitivity would not be continuous. There would be valleys of
| zero sensitivity between the cones, and a continuous wavelength
| sweep would result in us seeing black bands between colors.
| ComplexSystems wrote:
| Is this just my device, or is there no way to use this roll-your-
| own SVG generator to actually roll your own? I can only pick from
| a tiny subset of preset colors, most of which seem super random
| and desaturated and not what I want. There's no FFFF00 yellow,
| for instance. Is there some way to enter an arbitrary RGB color
| that I am not seeing? If not, why on Earth write such an
| interesting article, advertise this custom SVG generator and then
| build the interface that way? :/
| altairprime wrote:
| Does tapping on the horizontal color box to the right of the
| sentence "Select any color" under heading "Inside Color
| (Circle)" open a color picker? If not, perhaps your browser has
| a defective <input type=color> implementation, i.e. Firefox for
| Android [1796343]?
| vintermann wrote:
| Telenor's net nanny (which I didn't ask for) has decided that
| dynomight.net is dangerous and DNS blocked it.
| DavidVoid wrote:
| Ran into the same thing. Changing to a non-default DNS fixed
| it.
| perching_aix wrote:
| So change your router settings to offer a different default DNS
| via DHCP? Maybe configure your device(s) to use some other
| specific DNS servers rather than the ones offered via DHCP?
|
| For the site operator: the domain is present in the Spamhaus
| DBL (Domain Block List), which is presumably why these lovely
| gents are having issues, might wanna check that out.
| lubujackson wrote:
| Cross your eyes like a magic eye image when it's shrinking and
| the vivid color will expand to a larger patch.
| pixelpoet wrote:
| Incidentally the linked Skytopia page is that of Daniel White,
| who originally described the Mandelbulb:
| https://www.skytopia.com/project/fractal/mandelbrot.html /
| https://www.skytopia.com/project/fractal/mandelbulb.html
| weinzierl wrote:
| _" If you're colorblind, I don't think these will work, though
| I'm not sure."_
|
| Should work for anomalous trichromats (by far the majority of
| people with color deficiencies) but probably with less intensity.
|
| _" Folks with deuteranomaly have M cones, but they're shifted to
| respond more like L cones."_
|
| I don't think this is true. What would the difference between
| deutan and protan then be?
|
| _" Why do you hallucinate that crazy color? I think the red
| circle saturates the hell out of your red-sensitive L cones.
| Ordinarily, the green frequencies in the background would
| stimulate both your green-sensitive M cones and your red-
| sensitive L cones, due to their overlapping spectra. But the red
| circle has desensitized your red cones, so you get to experience
| your M cones firing without your L cones firing as much, and
| voila--insane color."_
|
| I think only people with missing L cone (Protanopia) or M cone
| (Deiteranopia) would not experience the phenomenon at all.
|
| Maybe this could be used as a new type of color deficiency test?
| peterisza wrote:
| A bit unrelated but I found this interesting: water is
| transparent only within a very narrow band of the electromagnetic
| spectrum, so living organisms evolved sensitivity to that band,
| and that's what we now call "visible light".
|
| http://hyperphysics.phy-astr.gsu.edu/hbase/Chemical/imgche/w...
| dennis_jeeves2 wrote:
| Interesting, given that most life is water based, most life
| will respond the most to this spectrum.
| rezmason wrote:
| I just want a display with a primary at 460nm. That's all I ask.
| perching_aix wrote:
| > If you refused to look at the animation, it's just a bluish-
| green background with a red circle on top that slowly shrinks
| down to nothing. That's all. But as it shrinks, you should
| hallucinate a very intense blue-green color around the rim.
|
| I do not believe I have any kind or amount of colorblindness, so
| imagine my surprise when extremely confused I pulled the image
| into MS Paint, used the Color Picker tool, and found that indeed,
| the background has quite a bit of blue in it.
|
| Anyhow, I cannot reproduce the illusion cited. For me the circle
| just blurs out and I start seeing orange.
| blincoln wrote:
| If you make the outer colour yellow using the custom colour
| option, and the inner circle red, do you see a an aurora-green
| halo? Or if you make the outer circle yellow and the inner
| circle green, do you see a red halo?
| perching_aix wrote:
| > If you make the outer colour yellow using the custom colour
| option, and the inner circle red, do you see a an aurora-
| green halo?
|
| You mean this, right? https://dynomight.net/img/colors/genera
| te.html?inside=ff0000...
|
| The background turns green (???) eventually, kind of like as
| if ink started to spread across it.
|
| Or you meant full yellow (255r, 255g, 0b) and full red (255r,
| 0g, 0b)?
|
| > Or if you make the outer circle yellow and the inner circle
| green, do you see a red halo?
|
| I used the controls this time and made the background full
| yellow (255r, 255g, 0b) and the inner circle full green (0r,
| 255g, 0b). Also adjusted the countdown speed, I realized I
| wasn't patient enough to wait out the 60s before ever (but
| that also it didn't need to be so long).
|
| During countdown the entire image turned green. Whenever my
| eyes would move a bit, I'd see either a 3D shadow depth
| effect or a yellow aura around the circle. When the circle
| started getting smaller I just saw the yellow aura. Whenever
| I'd drastically move my eyes, the entire background would
| revert to yellow, but would quickly go back to seeing green.
|
| I don't really see them being unusually saturated though, but
| maybe I just don't have a good grasp on what to expect. Maxed
| out R/G/B or C/M/Y all strike me as super saturated from the
| get-go.
| stouset wrote:
| I did see the illusion but I just did a double-take. That image
| looks just straight green to me. I suppose I could imagine it
| being greener somehow, but blue!?
|
| I have a slight deuteranomaly. I did see the illusion. Pretty!
| blincoln wrote:
| I did a custom combination of yellow outer field, blue inner
| circle, and got a vibrant purple halo, which is not what I
| expected. I assumed it would be "yellow++", based on what I know
| about the human eye's colour sensitivity.
|
| I didn't expect a _strong_ effect, because the overlap between
| blue and red /green is so much less than the overlap between red
| and green, but bright purple is close to the opposite of what I
| expected. I'm genuinely puzzled.
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