The internet abounds with techniques for teaching elementary schoolers the difference between warm and cool colors—an often-invisible, somewhat flexible line down the middle of the color wheel to separate warm reds, oranges, yellows, and browns from cool blues, greens, purples, and grays. The balance between them is said to enhance the beauty of Baroque landscapes and the Mona Lisa. Interior designers claim that cool colors recede and make rooms expand, while warm colors make rooms cozier.
Still, the basis for the warm-cool divide has remained murky, largely resting on the sometimes ambiguous and overlapping feelings different colors give people, as opposed to any clear scientific distinction. But a new study might change that: Across languages, it suggests, warm and cool colors can be distinguished by how easy they are to communicate. When you’re trying to describe a color to someone else, that person will identify the correct one faster if it’s warm rather than cool. This result has implications for the evolution of color vision in humans and other primates, and even the reason language developed to begin with.
The study, which was published Monday in the Proceedings of the National Academy of Sciences, asked people who speak three different languages—American English, Bolivian Spanish, and an Amazonian language called Tsimane—to play a guessing game. The researchers gave one participant (the speaker) a randomly selected color chip, then had them describe it to another participant (the listener) using a single color term. The listener picked out all the chips that could fall into the category described by the term—anything and everything that looks like a yellow, or a pink, or a green, and so on.