Language and perception (via @andrly)
“Several researchers studied the Himba color perception. The Himba use four color names: Zuzu stands for dark shades of blue, red, green and purple; Vapa is white and some shades of yellow; Buru is some shades of green and blue; and Dambu is some other shades of green, red and brown.
“The Himba color judgment is deeply affected by this classification. They find it difficult or even impossible to distinguish between colors that go under the same name in their system, while differentiating easily and immediately between close shades of color that they categorize under different names. This fascinating phenomenon is often said to demonstrate the deep effect language has over the perception of reality. So far the research does not rule out a genetic basis.”