nShowing relatedness between things.Color can enhance the Help file by adding interest and variety to the information. Unfortunately, color can also create problems that seriously limit its usefulness. Generally, color is good for grouping similar things and emphasizing elements but not good for conveying meaning. Because it is very effective, use it with care. Color can easily overpower the visual presentation of the Help topic and distract the user by drawing attention to itself and away from the other information. Color should complement a good layout rather than compensate for a bad one.
Color is good for:
nShowing relatedness between things.
Users tend to think of all the red items as being related to each other, all the blue items related to each other, and so on.
nCreating emphasis and showing visual hierarchy.
Color is a strong visual cue and an effective means of emphasis. Because it attracts the eye, a user’s eye will always move to the colored item in a black and white field. Bright colors attract the eye more than dull colors. That means colored elements automatically receive emphasis. Handled with good taste and judgment, color can help inform users and direct them to important information. However, when it is overused or used unwisely, color creates the wrong emphasis, and the topic may become difficult to read. Before you consider using color for an element, determine whether you want to give the item that much emphasis in the topic.
nShowing visual ordering, if you use the spectral order.
In other words, users see red, orange, yellow, green, blue, purple as being in order.
Color is not good for conveying specific meanings. Users can easily differentiate colored items from noncolored items, but they cannot easily associate a color difference with a particular meaning. For example, if you use color to symbolize different functions in the Help topic, users may learn that symbolism very slowly—green equals jump, red equals note, blue equals topic title, and so on. More than three text colors also make it difficult for users to keep track of the different meanings assigned to color.
nUse color sparingly, and only when it has a specific purpose in the topic.
Because color emphasizes, that emphasis can either enhance the information or detract from it, depending on how it is used. If color is used to make the topic look pretty, chances are it will also detract from the information rather than enhance it. So never use colors just for their own sake.
nDo not combine too many colors in the same topic.
Like other forms of emphasis, if color is overused it loses its impact. Two or three colors are often sufficient. More colors can be used if they help clarify the logical structure of the information, but too many colors destroy the unity of the display and decrease readability because the user’s eye jumps to the different colors. If black is used for body text and green for hot spots, that leaves only one additional color choice for text.
nUse color consistently.
For example, if green is used for hot spots, it should represent “hotness” throughout the Help file, no matter where it occurs.
nDo not use colors in ways that contradict their conventional meanings.
Green, for example, would not be a good choice for error messages. Remember, too, that meaning also depends on particular contexts: although green suggests ripe when talking about certain vegetables, it signifies untested when talking about a person’s experience.
nUse brighter colors for more important information.
Color has a luminance hierarchy that results in brighter colors appearing more dominant. For example, on a dark background a hierarchy of importance is white, yellow, cyan, green. If followed, the luminance hierarchy can complement typographical variations. If this hierarchy is ignored, the effects are very noticeable and potentially confusing. Distinctions between items that are not intended to imply an order of importance are best made by choosing colors close together in the hierarchy, for example, white and yellow.
nChoose a text/background color combination that maintains a high contrast between the characters and the background.
Letters on a background of the same luminance are extremely difficult to read because the eye cannot bring an edge into focus. On the other hand, a high contrast facilitates focusing. However, take caution when using dark text on a bright background. The contrast may be good, but the brightness of the display can make reading unpleasant.
nBe sure your design is acceptable in black and white.
Some users have monochrome monitors, so you should not rely exclusively on color for visual effects. In general, low-contrast colors do not transfer well to monochrome and grey-scale monitors. When displayed on grey-scale monitors, colors are converted to blacks, greys, and whites. That means you must choose colors so that the contrast between items is high enough to create contrast on a grey-scale screen. Otherwise, some screen elements may become invisible or very difficult to see.