Comment by ethbr1

At the end of the day, it's the "Is your green my green?" question and is unknowable.

You cannot describe something that someone lacks or has a substantially different subjective experience with, truly.

The best we can do is show that the effects of your seeing green are the same as mine (biologically, behaviorally, etc).

If you're curious about the broader subject, would highly recommend reading An Anthropologist on Mars.