"Harvard University, arrived in Tahiti in 1959 to study
island life, he expected to have a hard time learning the local words
for colors. His field had long espoused a theory called linguistic
relativity, which held that language shapes perception. Color was the
“parade example,” Kay says. His professors and textbooks taught that
people could only recognize a color as categorically distinct from
others if they had a word for it. If you knew only three color words, a
rainbow would have only three stripes. Blue wouldn’t stand out as blue
if you couldn’t name it.
What’s more, according to the relativist view, color
categories were arbitrary. The spectrum of color has no intrinsic
organization. Scientists had no reason to suspect that cultures divvied
it up in similar ways. To an English speaker like Kay, the category
“red” might include shades ranging from deep wine to light ruby. But to
Tahitians, maybe “red” also included shades that Kay would call “orange”
or “purple.” Or maybe Tahitians chunked colors not by a combination of
hue, lightness and saturation, as Americans do, but by material
qualities, like texture or sheen.
To his surprise, however, Kay found it easy to
understand colors in Tahitian. The language had fewer color terms than
English. For example, only one word, ninamu, translated to both
green and blue (now known as grue). But most Tahitian colors mapped
astonishingly well to categories that Kay already knew intuitively,
including white, black, red, and yellow. It was strange, he thought,
that the groupings weren’t more random.
Almost all of the languages they examined appeared
to have color words that drew from the same 11 basic categories.
A few years later, back in Boston, he was shooting the
breeze with a
fellow anthropologist, Brent Berlin, who had worked as a
graduate student among speakers of the Mayan language Tzeltal, in
Chiapas, Mexico. There, Berlin told Kay, he had encountered exactly the
same color categories that Kay had observed in Tahiti, including a
single word for grue. “The two languages are as unrelated to each other
historically as any two languages can be,” Kay says. And yet they seemed
to give rise to a common way of seeing and thinking about color.
The results revealed two remarkable patterns, which Kay and Berlin laid out in their 1969 monograph, Basic Color Terms.
First, almost all of the languages they examined appeared to have color
words that drew from the same 11 basic categories: white, black, red,
green, yellow, blue, brown, purple, pink, orange, and gray.
Second,
cultures seemed to build up their color vocabularies in a predictable
way. Languages with only two color categories chunked the spectrum into
blacks and whites. Languages with three categories also had a word for
red. Green or yellow came next. Then blue. Then brown. And so on.
Kay and Berlin took these commonalities as evidence that
our conception of colors is rooted, not in language, but in our shared
human biology.
More than a decade later, however, Kay and Berlin’s
revelations got some scientists wondering if color categories could be
anchored in something more innate. The wellspring, they suspected, lay
deep inside the human brain. But where?
Many color categories were consistent across cultures, suggesting a strong biological link.
Our color vision system, it turns out, is terrifically
complex. When light hits the human retina, it
activates three classes of
photoreceptor cells, called cones. Although all cones can respond to
all wavelengths in the visible spectrum, each type is most sensitive to
one particular slice: blue, yellow, or yellow-green. The relatively
small differences between these peaks allow the brain to do some pretty
sophisticated calculations, which determine the colors of the objects we
look at.
This code remains something of a mystery, but
neuroscientists are beginning to crack it. There is some evidence, for
example, that in the visual cortex, an information processing center
near the back of the skull, the brain adjusts signals relayed from the
cones to account for variations in ambient light, making a banana appear
yellow or an apple red whether it’s hanging in broad daylight or
perched atop a dimly lit counter.
Our ability to discriminate between “banana yellow” or
“apple red,” however, may arise near the bottom of the brain, in the
inferior temporal cortex, a region responsible for high-level visual
tasks such as recognizing faces, says Bevil Conway, .....he recently
found tiny islands of cells in this region that seem to be tuned to
specific hues, providing a sort of spatial map of the color spectrum.
That we have separate hardware for differentiating
colors and organizing them is telling, says Jules Davidoff, a
psychologist at Goldsmiths University of London." PocketWorthy/ChelseaWald
It was at the still hour, when
the gates of the day were closing, that with weary wing the dove came
back to the master: 
