How Many Colors Can We See?


Quick Questions cracks the code of color vision, color blindness, and even newly discovered sort of technicolor vision!
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  1. My guess is that I’m not a Tetrachromat. I know that I have perfect color vision – confirmed by various tests. I’ve also used color in a multitude of ways throughout my art/design career. Yet, I’ve known men – only a few – that are just as good with color. I’ve also checked out art from women who claim to be Tetrachromats and seem to experience what they describe. I actually know several women who can do the same. My guess is that several women claiming to be Tetrachromats really are not. I wish I could take a test to see if I actually see differently.

  2. You could have your genes tested to see if you are likely to have the extra cones. That would be a start. What do you mean by being good with color? Tasteful choices in home decor? or ability to perceive subtleties of tone and shade unseen by others? Slightly off your point is the proven ability of some people, (men included), to see in the ultra violet range of frequencies. However they are only able to discern it in terms of the violet that we all see, they don’t see a new colour.

  3. There’s a test described here though for some reason it’s in Comic Sans (perhaps to avoid getting too many hits from graphic designers?)

    Dr. Jordan set up an experiment in which subjects tried to determine whether a
    pair of colored lights matched. They used joysticks to blend two different
    wavelengths as they pleased. The resulting hues lay outside the spectrum of the
    blue photoreceptor, rendering it nearly useless, so that normal trichromats
    would have the use of only their red and green photoreceptors. Having hit upon a
    color, the subjects would then try to reproduce it by mixing two other
    wavelengths. Because the trichromats had the use of only two receptors, they
    found a whole slew of mixes that produced a matching color.

  4. While the range of colour vision in human cones appears to be variable, we need to remember that insects for example, can see beyond this range in the ultraviolet. Radio-telescopes, and the multi-spectral scanners used on space-craft can produce (false-colour) images across almost the whole spectrum of electro-magnetic radiation.

  5. Individuals with certain visual problems can see ultraviolet, but this is because of eye problems that are actually harmful. From my understanding Tetrachromats have an additional yellow cone. I would assume that this would punch up the greens and reds significantly.

    I also wonder if there is an ability for some to see infra red? Perhaps enhanced night vision.

  6. @Person

    It looks like Dr Neittz finally found Madam Tetrachromat otherwise cDa29 sometime between 2007 and 2012.

    Having sensors does not necessarily mean that we can consciously “see” with them. A comparatively recent discovery (2002 Sam Berman) was a class of retinal ganglion cels sitting outside the fovea, utilising photo-reactive melanopsin with a peak response at 482nm. These blue/green “peripheral vision” receptors cue our circadian rhythym and govern pupil dilation, without apparent conscious experience intervening.

    Oops, I may be wrong. It may be that conscious brightness perception (as well as pupillary diameter) occur with the stimulation of these photo-ganglions. Link follows…

  7. How different people perceive colour is one of those philosophical questions that has been asked many times but cannot really have a answer.
    How do I know that your brain perceives red the same way that my brain does? It is similar to the question of how do you know that someone else has consciousness and is self aware or are they just a high functioning machine.
    I have always wondered whether the brain is wired so that we all see the same limited range of colours even though some people may be able to see an extended range of wavelengths to others or do some people’s brains actually ‘see’ extra colours.

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