OTHER COLOR DESIGN GUIDELINES In addition to specific visual problems with particular color combinations, there are some more general concerns about use of color in graphic design. Use color sparingly, for specific purposes. Overuse detracts from the strength of the benefits of color. If color is used to visually group too many overlapping sets of symbols all of the visual grouping can be weakened. When drawing attention to symbols with color one is taking advantage of the "novelty" effect in human vision. Throughout human perception changes and departures from the norm draw attention. This effect, too, is reduced by repeated use. In this figure the grouping, labeling, and popout effects are stronger in the left panel than in the right. |
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More on grouping ; More on popout ; More on labeling . Avoid overuse of saturated colors. The biggest problem with overuse of vivid, saturated colors is that the overall neutralizing effect of overuse is worst for saturated colors (see previous guideline). There are also several undesirable visual side effects of saturated colors that can sometimes interfere with the intended communications. |
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Simultaneous and successive color contrast are serious concerns in some designs. Successive contrast is a result of looking at a patch of one color for a while, then looking at a different set of colors. The appearance of the second set is altered by the afterimage of the first color. Stare at the top left blue square for 5-10 seconds, then look at the small outline square below. You should see the aftereffect of the green and magenta fields as faint magenta and green fields, respectively. |
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Now repeat the experiment using the paler (less saturated) figure on the right. The afterimages should be much less visible--in fact, if you direct your attention to the left-hand figures without moving your eyes from the right-hand figure you can see that the afterimage on the left is stronger even in peripheral vision. In simultaneous contrast it is not necessary to superimpose an afterimage on the target. The apparent color of a target is always affected by the physical color of adjacent areas, in roughly the same color direction as successive contrast. The most serious
operational problem with simultaneous and successive contrast is
possible mistakes in identification of color-coded symbols. On the
saturated green and magenta backgrounds the two physically identical
squares
don't appear identical: The one on the magenta background looks
more like the upper square on the green background than the lower
square
due to interaction with the backgrounds. The influence of the backgrounds
is much smaller on the paler backgrounds. |
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Color can be a distractor in search tasks. Color can be a tremendous aid in drawing attention (popout) to target elements in search tasks, but it can interfere with search over dimensions that are not color coded or inappropriately color coded. For example, color coding of aircraft classes on ATC displays may interfere with monitoring of potential conflicts between aircraft of different classes. | ||||
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Use color consistently
across all of the user's applications. Assigning
the same color to different meanings in different parts
of the
user's work environment or assigning different colors to
the same meaning increases the user's cognitive workload. It also
increases the risk of the user making the wrong response for the
current context. Related Topics: Guidelines, Standards, and Requirements Pros and Cons of Guidelines, Standards, and Requirements Discrimination and Identification Color Guidelines Luminance Contrast Color Guidelines Color Guidelines Bibliography
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