Balloon 1 reflects R but not G or B
Balloon 2 reflects only G
Balloon 3 doesn't reflect anything
Balloon 4 reflects only B
Balloon 5 reflects everything
Balloon 6 reflects R and G
Our brain interprets "Red plus Green" as yellow -- we can't even
perceive that it is a mixture. Probably this is because in
natural light there is such a thing as true, pure yellow, that is
not a mixture of anything; our eyes can't tell that kind of light
from the mixture, and our brain has got enough to do without
warning us about this kind of possible confusion. It's only
in the manmade color world of computer monitors, color TV,
and color printing that yellow is more likely to be red + green
than its own natural self.
