4 ms·

Impossible colors

90 points by m0th87 16y ago

Natsu 16y ago
When I look at the blue/yellow thing on Wikipedia, I mostly get a headache. Depending on the angle I view it at, one color or the other dominates and it can change colors while I'm looking at it. I don't seem to get a blue/yellow unless you count where I can get it to be yellow in the middle with some blue at the edges that tends to merge with the black border.
- mechanical_fish 16y ago
  And I find that, hilariously, my visual system actively fights the merging of the boxes. When I successfully look at a real stereogram, there is a point at which my eyes snap into alignment and the stereogram pops out. In this case, it's like the opposite: I try to steer my eyes to the point where the blue and yellow boxes overlap, but if I get close they skitter apart. It's like trying to bring two identical magnetic poles together. I'm sure this stuff is highly idiosyncratic. Everyone's visual system is different. It develops via visual feedback at early ages and so is different for everyone, sometimes to one's detriment: http://www.lazyeye.org/ http://www.lazyeye.org/
  - Groxx 16y ago
    It would probably help if the "+" were a more visible color than white, as it gets lost a bit in the yellow when crossing.
  - long 16y ago
    My visual system fought back too. I'm normally able to free-fuse, but in this case my right eye just started hurting.
- thaumaturgy 16y ago
  I've seen the blue-yellow color only once before -- during a cluster headache. Seeing it again did not bring back the fondest of memories.
- jodrellblank 16y ago
  I don't get a single blue-yellow colour that I'm happy with, instead it either swaps from one to the other and back (patchily), or it holds semi steady as if I was looking at yellow through a blue mesh (or blue through a yellow mesh) but doesn't feel like a single colour, more like a checkerboard grid of two colours.
  - golgo13 16y ago
    I get the same checker effect. That, or I see a gradient of blue to yellow. Maybe it's just my LCD.
sudont 16y ago
Back when I was a wee art student, I had a phenomenal printmaking professor who was an expert in inks. One of her projects was a monotype, and mine included a cloud background, but I couldn't get the colors right: a dusky yellow cloud background. You've probably seen the hue following an afternoon thunderstorm late spring. I'd mix, and mix and end up with a dark yellow, that when printed over blue turned green, or reddish or some other stupid hue. And my printmaking professor came over, and she said to use gray, and some yellow, and some brown (please, don't ask for the exact ink mix). When we were done, the ink sat on the slab as a puce, but printed slightly yellow. However, when printed over a thalo blue, it was exactly like I needed: yellow-blue. Not green, yellow-blue. It was the damnedest thing, and not lost on the other students: I had to remix it at least six times within a week for other people. The color doesn't reproduce at all on screen, so I have to assume it's partially an optical illusion.
- jrockway 16y ago
  The color doesn't reproduce at all on screen, so I have to assume it's partially an optical illusion. I'm sure you know this, but RGB is not able to represent all possible colors, and monitors themselves are not able to represent all of RGB. This gives us a somewhat limited subset of available colors for use on screen, which is why (I assume) photographs don't look as colorful as the subject did real life. The film / CCD can't record all color information, and the print / monitor can't display it all.
  - malnourish 16y ago
    Is there any known, or conceivable technology, that would improve the color field for displays?
    - ZoFreX 16y ago
      There are "HDR" displays that can display a wider range of colours, my university had one.
      - 16y ago
burgerbrain 16y ago
As someone who enjoys both pesto pizza, and red wine, I can safely say that reddish-green does in fact exist.
bane 16y ago
Neon brown.
mitko 16y ago
They used to teach us elementary school that "blue+yellow=green". With the advance of science we fix some of our naive illusions. I don't know how many new we introduce...
mquander 16y ago
Also note imaginary colors: http://en.wikipedia.org/wiki/Imaginary_colors http://en.wikipedia.org/wiki/Imaginary_colors You can see some imaginary colors here: http://www.skytopia.com/project/illusion/ipage-et.html http://www.skytopia.com/project/illusion/ipage-et.html
- jarin 16y ago
  That Skytopia thing is crazy, you definitely need to stare for the full minute to get the effect though. Also, any time I do these afterimage experiments I notice that my eyes are not very well aligned.
  - mquander 16y ago
    Yeah, I was rather astonished the first time I tried it. I expected it to be unconvincing, but nope, that is definitely a brand new shade of cyan.
- tuhin 16y ago
  It just works!
- JshWright 16y ago
  So... does this blue circle go away eventually? Been a few minutes and I still can't look at a white surface without seeing a clearly defined blue circle...
  - Natsu 16y ago
    Yes, it goes away. But it may take a little while.
- JoeAltmaier 16y ago
  Ow.
- cskau 16y ago
  Wauw, this is a whole new HN - does it come as a Chrome extension ?
waqf 16y ago
I once read that colour-blind synaesthetes (or color-blind synesthetes, for you furriners) were able to perceive colours through synaesthesia that they were physiologically incapable of perceiving with their eyes. Thus they abnormally associated concepts with normal colours that were abnormal to them.
dsc 16y ago
I can't cross my eyes :(
sambeau 16y ago
This reminded me of a fact that astounded me when I first read it: Magenta is a colour created by our brain - there is no wavelength for it.
- pak 16y ago
  Right, although we have been trained otherwise by rainbow diagrams from birth, colors do not map 1:1 to wavelengths, and most of the light we observe is a mixture of wavelengths; we can only sample an intensity from each of three fuzzy bands of the spectra, and the rest is in our heads.
- Someone 16y ago
  Color is not a physical phenomenon, but a perceptual one; there are some wavelenghts that, in isolation, lead to perception of specific colors, but actually, there isn't a wavelength for any color. For example, one can have metameries (http://en.m.wikipedia.org/wiki/Metamerism_(color) http://en.m.wikipedia.org/wiki/Metamerism_(color)), where different physiclaal signals lead to perception of the same color.

90 points by m0th87 16y ago

Natsu 16y ago

When I look at the blue/yellow thing on Wikipedia, I mostly get a headache. Depending on the angle I view it at, one color or the other dominates and it can change colors while I'm looking at it. I don't seem to get a blue/yellow unless you count where I can get it to be yellow in the middle with some blue at the edges that tends to merge with the black border.

mechanical_fish 16y ago
And I find that, hilariously, my visual system actively fights the merging of the boxes. When I successfully look at a real stereogram, there is a point at which my eyes snap into alignment and the stereogram pops out. In this case, it's like the opposite: I try to steer my eyes to the point where the blue and yellow boxes overlap, but if I get close they skitter apart. It's like trying to bring two identical magnetic poles together. I'm sure this stuff is highly idiosyncratic. Everyone's visual system is different. It develops via visual feedback at early ages and so is different for everyone, sometimes to one's detriment: http://www.lazyeye.org/ http://www.lazyeye.org/
- Groxx 16y ago
  It would probably help if the "+" were a more visible color than white, as it gets lost a bit in the yellow when crossing.
- long 16y ago
  My visual system fought back too. I'm normally able to free-fuse, but in this case my right eye just started hurting.
thaumaturgy 16y ago
I've seen the blue-yellow color only once before -- during a cluster headache. Seeing it again did not bring back the fondest of memories.
jodrellblank 16y ago
I don't get a single blue-yellow colour that I'm happy with, instead it either swaps from one to the other and back (patchily), or it holds semi steady as if I was looking at yellow through a blue mesh (or blue through a yellow mesh) but doesn't feel like a single colour, more like a checkerboard grid of two colours.
- golgo13 16y ago
  I get the same checker effect. That, or I see a gradient of blue to yellow. Maybe it's just my LCD.

sudont 16y ago

Back when I was a wee art student, I had a phenomenal printmaking professor who was an expert in inks. One of her projects was a monotype, and mine included a cloud background, but I couldn't get the colors right: a dusky yellow cloud background. You've probably seen the hue following an afternoon thunderstorm late spring. I'd mix, and mix and end up with a dark yellow, that when printed over blue turned green, or reddish or some other stupid hue. And my printmaking professor came over, and she said to use gray, and some yellow, and some brown (please, don't ask for the exact ink mix). When we were done, the ink sat on the slab as a puce, but printed slightly yellow. However, when printed over a thalo blue, it was exactly like I needed: yellow-blue. Not green, yellow-blue. It was the damnedest thing, and not lost on the other students: I had to remix it at least six times within a week for other people. The color doesn't reproduce at all on screen, so I have to assume it's partially an optical illusion.

jrockway 16y ago
The color doesn't reproduce at all on screen, so I have to assume it's partially an optical illusion. I'm sure you know this, but RGB is not able to represent all possible colors, and monitors themselves are not able to represent all of RGB. This gives us a somewhat limited subset of available colors for use on screen, which is why (I assume) photographs don't look as colorful as the subject did real life. The film / CCD can't record all color information, and the print / monitor can't display it all.
- malnourish 16y ago
  Is there any known, or conceivable technology, that would improve the color field for displays?
  - ZoFreX 16y ago
    There are "HDR" displays that can display a wider range of colours, my university had one.
    - 16y ago

burgerbrain 16y ago

As someone who enjoys both pesto pizza, and red wine, I can safely say that reddish-green does in fact exist.

bane 16y ago

Neon brown.

mitko 16y ago

They used to teach us elementary school that "blue+yellow=green". With the advance of science we fix some of our naive illusions. I don't know how many new we introduce...

mquander 16y ago

Also note imaginary colors: http://en.wikipedia.org/wiki/Imaginary_colors http://en.wikipedia.org/wiki/Imaginary_colors You can see some imaginary colors here: http://www.skytopia.com/project/illusion/ipage-et.html http://www.skytopia.com/project/illusion/ipage-et.html

jarin 16y ago
That Skytopia thing is crazy, you definitely need to stare for the full minute to get the effect though. Also, any time I do these afterimage experiments I notice that my eyes are not very well aligned.
- mquander 16y ago
  Yeah, I was rather astonished the first time I tried it. I expected it to be unconvincing, but nope, that is definitely a brand new shade of cyan.
tuhin 16y ago
It just works!
JshWright 16y ago
So... does this blue circle go away eventually? Been a few minutes and I still can't look at a white surface without seeing a clearly defined blue circle...
- Natsu 16y ago
  Yes, it goes away. But it may take a little while.
JoeAltmaier 16y ago
Ow.
cskau 16y ago
Wauw, this is a whole new HN - does it come as a Chrome extension ?

waqf 16y ago

I once read that colour-blind synaesthetes (or color-blind synesthetes, for you furriners) were able to perceive colours through synaesthesia that they were physiologically incapable of perceiving with their eyes. Thus they abnormally associated concepts with normal colours that were abnormal to them.

dsc 16y ago

I can't cross my eyes :(

sambeau 16y ago

This reminded me of a fact that astounded me when I first read it: Magenta is a colour created by our brain - there is no wavelength for it.

pak 16y ago
Right, although we have been trained otherwise by rainbow diagrams from birth, colors do not map 1:1 to wavelengths, and most of the light we observe is a mixture of wavelengths; we can only sample an intensity from each of three fuzzy bands of the spectra, and the rest is in our heads.
Someone 16y ago
Color is not a physical phenomenon, but a perceptual one; there are some wavelenghts that, in isolation, lead to perception of specific colors, but actually, there isn't a wavelength for any color. For example, one can have metameries (http://en.m.wikipedia.org/wiki/Metamerism_(color) http://en.m.wikipedia.org/wiki/Metamerism_(color)), where different physiclaal signals lead to perception of the same color.