I thought this was a very interesting discussion on the properties of color when it comes to projected light. When I give my color theory lecture in my design class I have to explain how the properties of color are completely different depending on whether you are dealing with projected light or reflected light.
When light is being projected from a light source such as a digital projector or a television the three primary colors are red, green and blue; hence the initials RGB. And when you mix those three primary colors together you get white light.
But when white light is reflected off of an object that does not itself emit light, such as a painting, the primary colors you would use to mix the colors on that painting would be red, yellow and blue. And when you mix all three of those primaries together you end up with black or dark brown paint.
And then to complicate matters even further, I explain that the three-color printing process has still it's own set of primary colors. If you've ever had to replace ink cartridges in your printer you know that the three primaries for printers are magenta, cyan and yellow.