The concept of the color wheel was invented when Sir Isaac Newton bent the color spectrum into a circle. Since then, the color wheel has been used as a tool for understanding color relationships and creating harmonious color schemes. The color wheel clearly shows which colors are warm and cool, complementary, split complementary and analogous. The diagrams in the following pages demonstrate each of these concepts.
Cool colors range from blue to violet, the half of the color wheel with shorter wavelengths. Cool colors have a calming effect. They are frequently used for backgrounds to set off smaller areas of warm colors. Used together, cool colors can look clean and crisp, implying status and calm. However, it is important to note that usage of bright cool colors generates more excitement than light, medium or dark cool colors.
Warm colors range from red to yellow, essentially the half of the color wheel corresponding to the longer wavelengths. Warm colors are active, attention-grabbing and aggressive. They stimulate the emotions, motivate and seem to come forward off the screen or page.
Complementary colors lie opposite each other on the color wheel. They complete or enhance each other. Impressionist painters in the 19th century often placed dots of pure complementary pigment on a color's surface to make the color come alive. While the dots weren't apparent to the viewer, the color appeared especially vibrant.
When mixed together equally, subtractive complements, such as paints, should theoretically produce black or gray. In practice, the pigments are never perfect and the result is a muddy brown instead.
Using complementary colors in an image is quite pleasing to the eye. The colors seem to belong together. The most effective use of complements is to let one of them dominate by giving it a bigger area or a fuller saturation, while using the other as an accent.
Split complements (also known as contrasting colors or triads) lie on either side of a color's complement on the color wheel. These colors offer many of the same benefits as complementary colors, but the effect is more subtle. As two of the colors will be very similar, using fully saturated colors may be too strong. Dilute the saturation by using darker shades or lighter tints to draw the colors together.
Analogous color schemes use colors that are adjacent on the color wheel and so have similar hues. For example, blues, blue-greens and greens are analogous. When using analogous colors in a presentation, make one color dominant to avoid confusion and use the other colors as accents.
A monochromatic color scheme uses a single hue with variations in the saturation and brightness only. Such a color scheme produces simple images with no discord. However, if you plan to use monochromatic colors for your business graphics, make sure that you have the contrast necessary to make clear distinctions for the audience and to emphasize the important points. This is also important for achromatic graphics, which use white, black and shades of gray.
Achromatic color schemes have no color. They use black, white and shades of gray to represent colors. It may be that while your graphics will be presented in color, you'll need to produce black-and-white handouts. If so, review each handout carefully for legibility, as colors don't always translate to grayscales as expected. If a grayscaled image isn't clear enough, consider replacing blocks of color with patterns to increase legibility.