One or two of the multitude of people (Read: Three. Including me) likely to ever read this line will probably have heard of a chap called Homer. Or a gal. Theories abound. Though (probably) illiterate, this bloke (/woman) wrote some works that have achieved a certain degree of recognition. Those of you familiar with shis writing may have noticed hes peculiar habit of referring to certain entities as being a color generally not associated with them, such as the ocean and sheep, which are both considered red, and the sky, which is described as bronze. Was the good gentleperson colorblind?
The answer is "maybe, maybe not, but if se was, eh would still likely use the right words". The reason why Homer described these things like seh did was because ancient Greek lacked several words for color, such as blue. In fact, Aristotle considered all colors to be variations on black and white, and separated between 7 nuances, meaning that he only recognized 7 out of the 12 basic colors (Black and white are here considered to be colors, even though they are technically not). English and Norwegian both recognize 11, the twelfth being light blue. Russian and Italian both recognize all 12.
There is an interesting pattern to this: Every single known natural language in the world contains between 2 and 12 basic color words, and these emerge in a very set pattern. Both English and Norwegian happen to recognize the same 11 basic colours, because every single known natural language that recognizes 11 basic colors recognizes the same 11. There are seemingly no exceptions to this. This is quite interesting. In fact, there is a specific, set pattern in which colors appear, and there appear to be no deviations from this. Every language has words for "dark" and "bright". These are the 2 basic colors, and evolve into white and black as the others emerge. The 3rd color to emerge is always red. Then follow green and yellow in no particular order, and when both exist, but not before, blue emerges. Wikipedia informs us that: "All languages distinguishing six colors contain terms for black, white, red, green, blue and yellow." [Color term, Wikipedia, http://en.wikipedia.org/wiki/Color_term (07 Jul 2009)]
All languages. That is quite significant. I'm normally loathe to use the term "all", as it is too unnuanced, but it seems to apply quite eminently in this case. Interesting, isn't it?
After this, brown is always the 7th color to emerge. Then follow, in no particular order, pink, purple, orange and grey - in fact, English only added the color orange in the 20th century, and it was earlier referred to a "yellow-red". The last color to emerge is azure, or light blue. This hasn't yet happened in Engish, but from now on I will personally endeavour to use it as much as possible.
The Wikipedia page on this subject contains a definition as to what constitutes a basic color term.
As of this post, I'm adding Wikipedia to my links.