Colors

Colors are one of those things for which we have no descriptions. There is no way to really objectively describe a color, rather, you must be shown it. How would someone describe the color blue to someone who has never seen blue? The only way to really describe color thus far is to describe it in relation to another color. For instance, you'd describe purple by saying it was like a mix of red and blue. You could describe pink by saying that it was a light shade of red. In these ways you can approximate a description, albeit one that relys on the other person having some knowledge of color already.
The other thing is, how do I know that me and you see the same colors? Theres no way to tell here either. When we were both younger, we learned what the color green was. Green was that color that the trees and grasses were, and the outside of watermelons, and the top light on a stoplight. That was green. But maybe the color I percieve as being green is the color you percieve as being yellow. Would there be any way to really tell? I would still point at a tree and say "hey, thats green." and you would agree. Because we cant describe color, theres no way to know for sure.