This is an actual thing talked about. Like we know people SEE colors but our brains might interpret them completely differently than someone else and since we can’t actually describe colors outside of how we see them, there is no way to actually prove that our brains interpret colors in the same ways as other people.
It’s a fun thought to chew on but ultimately goes nowhere because it can’t be studied or tested in any way. I like it because it makes us question what we’ve all just assumed everyone else is experiencing and seeing is the exact same as us when it could actually be entirely different than what we see.