I'd have to dig up references, but I understand it's a pretty well documented effect that having words for colors is directly related to a population seeing more distinction for those colors.
If I recall, some early societies didn't have a distinction between green and blue. Given that blue often doesnt show up naturally outside of the sky and it's reflections. And in those populations they would be much less sensitive to distinctions in blue-green.
If I recall, some early societies didn't have a distinction between green and blue. Given that blue often doesnt show up naturally outside of the sky and it's reflections. And in those populations they would be much less sensitive to distinctions in blue-green.