Melody Dye has a very interesting article in Scientific American on why it’s so difficult for kids to learn words for colours, and how it can be made easier for them:
psychologists have found that even after hours and hours of repeated training on color words, children’s performance typically fails to noticeably improve, and children as old as six continue to make major color naming errors. This is seriously bizarre when you consider all the other things that children at that age can do
Different cultures divide the colour spectrum differently – sometimes subtly so, sometimes drastically. This means that learning colour terms requires children to learn not just the words but the particular colour map that obtains in their culture. And since colours are ubiquitous and blend into one another, it naturally takes a while to sort it all out.
This process might be particularly tricky in English because
we like to use color words “prenominally,” meaning before nouns. So, we’ll often say things like “the red balloon,” instead of using the postnominal construction, “the balloon is red.”
Dye explains why this matters: it has to do with how our attention works. Understanding this means we can help children learn colours more quickly by adjusting our syntax slightly in a way that will direct their attention in a particular way.
The article is well worth reading, and there are many links for the curious. [Edit: It was published about a year ago, so some of you will have already read it. Somehow I saw it only recently.]
Update: The same principle also applies to number learning.