To take our foundational knowledge of color any further, we’ll need to gain a grounding in some of the more technical concepts associated with the subject, such as how colors are formed and how they can be categorized.
The colors displayed on your computer screen (that is, the colors we’ll be using in our website designs) are based on an additive color model. In an additive color model, colors are displayed in percentages of red, green, and blue (RGB) light. If we turn all three of these colors on full blast, we’ll have white light. If we turn red and green all the way up, but switch off blue, we have yellow.
If you’ve ever owned a color printer, you might be familiar with the acronymCMYK (cyan, magenta, yellow, and black). Your ink-jet printer, laser printer, and industrial four-color printing press all create images using cyan, magenta, yellow, and black inks or toners. This process uses a subtractive color model; by combining colors in this color model, we come close to achieving a grayish black. There’s no way of producing black combining just cyan, magenta, and yellow. This is why they’re always supplemented with black — the K in CMYK. Take a look at Figure 3, “RGB additive color model (left) and the CMYK subtractive color model (right)” for a better idea of how additive and subtractive color models work.