The language bit here is about how people “respond” rather than “perceive.” They might use the same word for two colors, that doesn’t mean they cannot “see” or “understand” that green and blue have differences. It is also about the question you ask them: “what color is this?” vs “which of these is darker?”
sahnti t1_iudkqb3 wrote
Reply to comment by blow_up_the_outside in ELI5: Why are the colours in rainbows in separate lines? by Oheligud
The language bit here is about how people “respond” rather than “perceive.” They might use the same word for two colors, that doesn’t mean they cannot “see” or “understand” that green and blue have differences. It is also about the question you ask them: “what color is this?” vs “which of these is darker?”