Additive and Subtractive Color
Color can be defined in two independent frameworks, known as additive and subtractive processes. As we have seen, color is created by the absorbing of wavelength of light. When an object absorbs these wavelengths, it is subtracting those colors from the spectrum of color contained in the white light that reaches it. Subtractive color processes are found in the missing of paint and pigments. In this system our primary colors are red, yellow and blue. These are the colors from which all other colors can be created. When we mix red and yellow pigment together to create orange, we are submitting out wavelength of color. The more we mix color together, the more color wavelength is absorbed (subtracted). When all the three primaries are mixed together, the result is black. Black can be thought as the absence of color: subtracting out all of the wavelengths contained in light.
The additive color system is defined in terms of light. It is the color model used for film, computer and television monitors and projected light based presentations,. In this system, the primary colors are red, green and blue often referred to as RGB. Additive secondary colors are cyan, yellow and magenta. Adding equal amounts of the primary colors will produce white. How we mix colors is very different depending on whether an additive or subtractive color process is used. The process if mixing paint for the projects in this class will develop a sensitivity to color which will ultimately benefit the computer artist as well as the painter. It is important to be aware of both systems of color: whenever you design an image using a computer monitor and then print it out, you are using both the additive system and subtractive system of color.
In this class we will only use the subtractive process in describing and exploring color theory. If you are interested in the additive color process, you should experiment with mixing colors using RGB in Photoshop for additional understanding and exploration.