Do Not Rely on Color Alone to Convey Meaning

Requirement: Information presented will not rely on color to convey meaning. In addition to or in place of color, appropriate markup and text-based cues should be given.

Fails to meet this standard

Please fill out the items marked in red.

Meets this standard

Please fill out items marked with an * and in red. Developers should also consider using markup in addition to text-based cues to alert users to certain important information. For example, use the emphasized elelment <em></em> or the strong element <strong></strong> to call attention to important content.

Why this is important

For no- and low-vision users who cannot see color, cues based on color alone are meaningless. Also, many people have various levels of color blindness; what may appear as red to some, appears as gray to others.