The color combinations you place on slides significantly affect their visual impact and appeal. Keep in mind the following characteristics: Reds, oranges, and yellows are referred to as warm colors. They tend to pop out and attract attention, especially red. Greens, blues, and purples are cool colors. These colors recede into the background and draw less attention (Figure 1).White and very light colors also catch the eye, whereas black and very dark colors generally are less noticeable.
Interestingly, the above effects are not absolutely fixed. They can flip, depending upon the quantity of one color present compared with another. For example, if you were to place a small black shape on a solid white slide background, the black shape would pop out as more noticeable than the white background (Figure 2).
In this case, the brain is looking for meaning in the display rather than simply reacting to color characteristics. Not surprisingly, some optical illusions take advantage of this phenomenon. Realize, therefore, that the quantity and contrast of colors can be important to slide designs. This issue is most critical in a PowerPoint sense regarding text usage. Use opposite extremes of light verses dark between text and backgrounds. If the slide background is light, use black or very dark text for best results (Figure 3)—unless, of course, you are intentionally creating some form of subtle effect, such as making Navigation Elements less distracting.
There is an interesting and complex interplay between color characteristics, contrast, and quantity. We’ll focus here on color characteristics and interactions. How you combine colors definitely affects a design’s overall desirability.
NEVER do what is depicted in Figures 4 and 5.
If you stare at either of these images for very long (especially on screen), your eyes begin screaming. Mixing bright blues and reds is a terrible practice to inflict upon an audience, and unfortunately it happens more often than one would hope. The same goes with mixing reds and greens. The color interactions are harsh and fatiguing to the eyes.
A red and green combination also brings up the issue of color blindness, which apparently affects somewhere around 7 percent of men and less than 1 percent of women. Difficulty distinguishing between red and green is the most common form of color blindness. If you place green text on a red background, and there is not a lot of contrast between the colors, some viewers will not be able to read the text. Avoid such problems across the board by never mixing these two colors, especially in a text-background combination.
An interesting technique florists sometimes use is to fashion a bouquet of uniformly colored flowers—say yellows or oranges—and then throw in two or three bright red flowers, off center and at different levels in the bouquet. Your eyes are naturally attracted to these bright red spots, but your brain can’t really make up its mind which red flower should be the focus. So it shifts back and forth between them, causing you to inadvertently scan the entire bouquet. In a related way, dark green foliage is often included with a bouquet to act as a frame and allow bright, warm-color flowers to stand out and attract more attention.
When it comes to mixing colors, here are broad guidelines:
As a rule, mixing warm colors with each other or mixing cool colors with each other is safe. You’ll notice Aspire’s color scheme featured throughout the Web site and Relational Presentation books stays with warm colors. Most companies prefer a cool combination, especially blues, grays, teals, and black.
Black and white work fine in combination with all other colors, as does beige, surprisingly. For example, you can get away with having light beige text on a dark blue background equally with placing it on a dark red background. Browns, however, are best combined with warm colors (Figure 6). Grays fit better with cool colors (Figure 7).
Mixing warm and cool colors is risky and is best left to graphic design contexts. Such color combinations can look fine in graphics (Figure 8) because graphics often use complex gradations and mixtures of colors. Without such subtleties, mixed warm-cool colors on slides tend to portray the gaudiness of sports uniforms.
With text, the same mixing guidelines apply. For text used as content, we almost always use white or beige on a dark background, or black on a light background. Above all else, you want observers to be able to read the text easily. When text is graphical in nature, such as a label or title that is part of a picture, just about anything goes. Again, such text should be easily readable, but color and design can vary considerably.