About 150 years ago, a British scholar named William Gladstone was studying Homer’s "The Odyssey" and noticed that the poet had some unconventional descriptions of color. For instance, honey was described as green, while iron was called violet. However, no mention of blue existed. Similar investigations into ancient texts of a number of other languages were also missing any mention of the word blue. In fact, the first mention of blue wasn't found in any language until about 4,500 years ago. Was it possible that they weren’t able to perceive it as we do now?

Psychologist Jules Davidoff traveled to Namibia in order to conduct an experiment with the Himba tribe. Their language has no distinct word for blue, and when asked to choose a blue square among a group of green squares, they had extreme difficulty.