There wasn’t an English word for the color “orange” until 200 years after the citrus fruit of the same name arrived in Europe. Before then, the color was called by the two other colors that, when mixed, make orange: “yellow-red.”

This is just one striking example of the ways in which color categories are shaped by culture. Ancient languages, including Greek, Chinese, Hebrew, and Japanese, didn’t have a word for blue. And Russian speakers have two distinct category words for light blue vs dark blue: Something is never “blue,” in Russian, it’s either “siniy” (dark blue) or “goluboy” (light blue.)

These words don’t simply reflect what we see, but multiple experiments suggest they influence our perception. In one recent study, published in Psychological Science and reported by the British Psychological Society, researchers showed groups of Greek, German, and Russian speakers (103 people in total) a rapid series of shapes, and were told to look out for a grey semi-circle. This semi-circle appeared alongside a triangle in different shades of blue and green, and participants later reported whether they saw a complete triangle, a slight or strong impression of the shape, or didn’t see it at all.

Researchers found that Greek and Russian speakers, who have dedicated words for light and dark blue, were more likely to see a light blue triangle against a dark blue background (and vice versa), than they were to identify green triangles against green backgrounds. Speakers of German, which has no such distinction, were no better at seeing shades of blue triangles than green.

Similar research has found that Russian speakers distinguish between shades of blue faster than English speakers, and Greek speakers start to see all shades of blue as similar after living in the UK for a long time.

The idea that language influences reality is called the “Sapir-Whorf hypothesis,” after its originators Edward Sapir and Benjamin Lee Whorf. There’s ongoing debate about the extent to which Sapir-Whorf applies: Perhaps there are a few universal categories of color that are perceived the same around the world, regardless of the words we use for them. For example, though have thousands of color words, they all tend to rely on just a handful of basic colors. Linguists have identified 11 basic color terms (pdf) in English, each of which is indivisible without being a shade of another color: black, white, gray, red, green, blue, yellow, pink, orange, purple, and brown. But, of course, it wasn’t too long ago that those who spoke English couldn’t enjoy an orange sunset—they had to settle for one that was yellow-red.