Humans can mix channels to create an infinite variety of perceived colour through combination. We can even see pink, which doesn't exist in the EM spectrum. It's a colour that only exists in the minds of living beings.

Mantis shrimp brains are too simple to mix channels. They can only recognise the presence of absence of the 12 colours their eyes can see. While a mantis shrimp can see infrared, ultraviolet, and polarisation, a mantis shrimp will never know the beauty of blurple, electric lime, hot pink, or any of the thousands of other colours humans can see thanks to channel mixing.