Color is sometimes used to convey meaning beyond the basic text. For example, in a course syllabus, you may use color to emphasize an important statement. Or, on a PowerPoint slide showing a multiple choice question, you might show the correct answer in green, but color the incorrect answers in red. Using color to communicate meaning or emphasis is problematic for students with color blindness. If you want to use color to express meaning, you should also provide a supplemental means to convey the information without color.
A related issue is contrast. People who have some vision loss may have difficulty discerning changes in contrast color. When choosing font and background colors, make sure the contrast is strong enough to enable those with some vision loss to read the text. If the background is dark, the text should be a light color; if the background is light, the text should be dark. Avoid neon colors altogether and test readability with multiple devices.
Our effort rating for this task was low because it is easy to avoid using color to convey meaning. We decided on a low rating for impact as well because we do not encounter this issue in our practice as often as some of the other activities in our matrix. In cases we have encountered, the use of color to convey meaning is often redundant, as when a student’s grades that fall below a certain level are displayed in red. Although the color draws attention to the number, the number itself accurately conveys the meaning.
In a good example, survey results reported by gender would display data from males in a red font followed by an asterisk. Colorblind students could identify male data by the asterisks, rather than the colored font.
A poor example might consist of a form in which required fields are denoted in red without any additional indicator that conveys the meaning.
- For additional information on accessible responses to color blindness, read the WebAIM article entitled Visual Disabilities: Color-blindness.
- WebAIM also publishes a Color Contrast Checker to help you visualize how different colors contrast with one another.