I think the basic point of the original write up in this node has been missed slightly.
Suvrat (I believe) was just simply asking the visual equivalent of "If a tree falls in a forest, and nobody's around, does it make a sound?" In other words, would color exist if there were no eyes around to perceive the light and its many wavelengths?
Being a fine artist and one-time painter I know quite a bit about color theory and what colors to mix with what to get what. As such, I have often in my mind wondered, usually while in art classes, "What if this red I'm seeing actually looks like what I perceive as yellow to that person over there? Is this impossible to know?" But only in my mind, because I was afraid of sounding crazy. I was relieved to see this node and that others have had the same thoughts.
I have always wanted to somehow see what it was like to see the world through another person's eyes just for a moment. Maybe nothing would look different. Maybe everything would. It's one of those things that will eventually drive you crazy if you think about it long enough.
Like the tree falling in the forest thing.