" The cultural significance of blue, on the other hand, is very limited. As noted earlier, blue is extremely rare as a color of materials in nature, and blue dyes are exceedingly difficult to produce. People in simple cultures might spend a lifetime without seeing objects that are truly blue. Of course, blue is the color of the sky (and, for some of us, the sea). But in the absence of blue materials with any practical significance, the need to find a special name for this great stretch of nothingness is particularly non-pressing. "

― Guy Deutscher , Through the Language Glass: Why the World Looks Different in Other Languages