How “blue” and “green” appeared in a language that didn’t have words for them - eviltoast
A new study suggests the way a language divides up color space can be influenced by contact with other languages. Tsimane’ people who learned Spanish as a second language began to classify blue and green into using separate words, which their native tongue does not do.

The article shows a case of language contact (Tsimané vs. Spanish) triggering the conceptual split of a colour into two.