There are three types of cone cells in the human eye that are sensitive to red, green, and blue, so the color system that most closely aligns with the human eye is the red-green-blue color system. There are two ways for creating the color we see - additive and subtractive. In an additive color system, light (and color) is created directly (using light) so the primary colors are simply red, green, and blue (RGB). Computer screens and televisions are examples of additive color.

In a subtractive color system, such as printing, photography, and painting, a reflected color is obtained by absorbing (subtracting) the opposite color. The most effective primary colors of an subtractive color system are the opposites of red, green, and blue, which just happen to be cyan, magenta, and yellow (CMY).

So we have two scientific primary color systems, additive (RGB) and subtractive (CMY), and then we have the "artist primary system" (RYB) which is not based on science and is not particularly effective. Artists are still clinging to an outdated model of a color primary system.

Does using an outdated primary system actually make a difference? It is difficult to mix colorful greens, cyans, purples and magentas using the three colors of red, blue, and yellow, but most artists use more than three colors. Unlike photography and printing, painters can use variations of reds, yellows and blues. And even a simplified palette can be incredibly powerful. Just take another look at some Zorn paintings where he used black, vermillion, ochre, and white. However, it is quite possible our critical thinking (and mixing) skills are compromised when we cling to an inaccurate primary system.

Is our dependence on cadmium red a result of red, yellow, blue thinking? While cadmium red is useful, it is not nearly as useful for mixing as a red that leans more towards magenta, such as alizarin or quinacridone. Think about the possibilities of alizarin, mixed with a blue such as cyan, or alizarin mixed with yellow. Now consider what happens when cadmium red is substituted for alizarin.

Also, words matter. The complexity of visual processing is both enhanced and inhibited by the language centers of the brain. It's possible that what we name a color can change how we see that color.

Artists are dealing with the perception and psychology of color. Our job is to interpret, not to try and replicate, so we can grant ourselves some leeway and a free pass when mixing color. But light is the science of additive color; pigment is the science of subtractive color; light is a physical entity; and seeing color is a perception. Let's not make this any more confusing than it already is.

Why the world map you know is wrong

In yet another example of inaccurate and misleading information, we are still using a world map created in 1596. The original map was made by a globe maker named Mercator to help sailors navigate the world, and its distortions and exaggerations are the result of the difficulty inherent in portraying a spherical world on a flat map. Imagine stretching a map on a globe to fit a rectangular space.

Despite attempts at other projections, the Mercator map has maintained its dominance over centuries and is now used at Google Maps and Bing. We think Greenland is huge, but in reality, it is about four times smaller than the United States and 14.5 times smaller than Africa. Greenland is actually about the size of Saudi Arabia. Africa is larger than Russia and Brazil is more than five times larger than Alaska.

Want to learn more? Check out the app The True Size of.