Overview
Color should not be used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.
Ensure that all sighted users can access information that is conveyed by color differences, that is, by the use of color where each color has a meaning assigned to it. If the information is conveyed through color differences in an image (or other non-text format), the color may not be seen by users with color deficiencies. In this case, providing the information conveyed with color through another visual means ensures users who cannot see color can still perceive the information.
Color is an important asset in the design of Web content, enhancing its aesthetic appeal, its usability, and its accessibility. However, some users have difficulty perceiving color. People with partial sight often experience limited color vision, and many older users do not see color well. In addition, people using limited-color or monochrome displays and browsers will be unable to access information that is presented only in color.
Provide sufficient contrast:
Between text and its background, so that it can be read by people with moderately low vision or impaired contrast perception, without the use of contrast-enhancing assistive technology.
Between link text and background color.
Between link text and surrounding body text.
Color Contrast Between Text and Background Color
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