Robert asked:

A simple question: How do you describe a color that you never saw before?

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I believe that's a moot question, since by the time children learn to describe colours, they have
typically seen those colours more than once. In fact, learning to describe colours would seem to
depend on noticing that adults do not merely call this"green", but also this, thisand this, which
resemble it in a certain way.

T. P. Uschanov

Research Assistant

Department of Philosophy

University of Helsinki

A simple answer: Research into the psychology of colour has established that all primary and at least
some secondary colours are universally recognised by all human beings irrespective of their social
upbringing. However, the namingof these colours shows occasional inconsistencies which do
depend on social conventions. Now naming is not an innocent (irrelevant) factor, and so it happens
that researchers equipped with colour charts will find themselves every so often amid one or another
native tribe (usually nomads) who use the same word (say: "dark") for all colours that seem dark
without apparently distinguishing red and blue and green. And so on. Yet in spite of this, when
confronted with the flora and fauna of their habitat, they readily distinguish purple from orange and
other subtle variations. Clearly, there is an evolutionary endowment among us humans to make such
distinction based on hierarchies in the visible spectrum; and part of this endowment is an intuitive
(admittedly not infallible) skill in establishing the relation of certain hues to their sources. E.g. purple,
mauve and turquoise all have some blue in them, yet purple is unfailingly perceived as "red". So if
you see a colour for the first time, your obvious starting point would be fromthe primary (pigment)
colours yellow, red and blue, from there to their mixtures orange, brown and green. Already this
covers a large percentage of the visible spectrum; your reference point from any unknown colour
would be to this ensemble (plus, obviously black, white and grey). There is no colour conceivable to
us that would not show one of these as a recognisably prevalent.

In short, for the sake of the exercise, look at aquarells, where the colours tend often to be very subtle
shades and try to find one that is plainly not referable to one the above. But if you have a conception
of (say) blue and you encounter mauve, you could always say: "Well, some sorta blue... kinda blue
minus... like a bit of white thrown in"; and already you're halfway to its place in the spectrum. —
Anyway, this is not really a philosophical topic and this rough guide may suffice you to start your
research. The best place to look for information is under the heading of design with colour.There is a
huge volume of technical information (look also for the name "Itten").

Jürgen Lawrenz

Sydney

You mean, if you're an interior designer, and you want to inform your clients about new wallpaper? Or
do you want to describe color to a color-blind person? Or do you mean that youare trying to describe
the color to yourself,and you've never seen it before? There's always metaphor: "it's a warm red,
warmer than fire-engine red". How about that? Or, "it's a combination of purple and greenish-yellow".
Or, "no, chartreuse is green, not purple". Like that? Or are you asking what it is for the aliens around
Orion to see x-rays? I'd guess they'd have to use metaphor to describe it to us also, wouldn't you?

Or are you asking whyyou have to use metaphor? Now, that's a more interesting question, and I'm
not sure that anyone has the answer, completely. But if you look at how the brain's color system
works, you find that there are certain "primary" colors, determined by absorption characteristics of
pigments in the cones on the retina; and in the brain, those are refined and combined, andprocessed
by an opponent-color system which contrasts "complementary" colors. It's very, very, complex. But
the result is that there are particular relationships between colors, described in part by a "color
wheel", and those relationships incorporate a great deal of asymmetry. So it is not possible, for
example, to combine red and blue in the same way that yellow and purple are combined, for a variety
of reasons. Take a look at Palmer, S. E. Vision Science: Photons to Phenomenology.Cambridge,
MA: The MIT Press, 1999. And that,in a nutshell, is why you need metaphor... the laws are a)
extremely complex, and b) not all known yet.

Yes, this is a simple question in the sense that "how does a tomato grow" is a simple question; it's
easy enough to ask.

Steven Ravett Brown

A simple reply: probably by analogy with colors you have seen before. Suppose you had never seen
green before. You might describe it as a kind of blue with a yellow tinge.

John Locke, the English philosopher, once talked about trying to describe the color scarlet to a
congenitally blind person. He suggested saying it was like the blast of a trumpet.

Ken Stern