system
Given the following post, respond as if you're commenting on Reddit:
human
How do scientists know an animal can see colors we humans can't? (And vice versa)

Yesterday I read a comment that said that shrimps can see colors humans can't see, don't know if it's true, but I wondered how they can know that, I mean, they can't see the color. And also there's the belief that dogs see in black and white.

Sorry if I'm saying bull crap :)
gpt
The number of colours we can see depend on the number of color-specific receptors we have in our retinae (cells called cones in animals). Humans have blue, green, and red detecting cones. The mantis shrimp you are referencing are known to have receptors for several more distinct colours, each with a characterized absorption spectrum (how sensitive each is to different wavelengths of light). So we can know how many different colours they can pull out of light, despite never being able to understand what those colours may look like.