Science Buddies: "Ask an Expert"

I was curious as to why the 3 color circle, in the afterimages project, uses 2 primary and 1 secondary colors (red, blue, and green) instead of all 3 primary colors (red, blue, and yellow)? Thank you

Hi,

The reason for this is that humans have three types of cone cells in their eyes, but they do not correspond to the three primary colors (red, blue, yellow). Take a look at this article on Wikipedia: http://en.wikipedia.org/wiki/Color_vision and see if it doesn't answer your question more thoroughly.

Good luck!