Careful use of color

Avoid using color as the only indicator of important information

When including color or sensory-based instructions (e.g., size, shape, position, etc.) in a document, provide supplemental information for users with visual impairments. 

Sharp contrast between the text and background colors help individuals read the content regardless of visual impairments or the content medium. Low-color contrast can often make text illegible. Try to use simple, high-contrast color combinations such as black on white or white on black.

For example: “The assignments in red contained in the box on the left side of the page are due next week.” would be difficult to understand for individuals with visual impairments, since they might not be able to tell which assignments were marked red.

However, “Look in the Weekly Due Date section under the Assignments heading. The assignments in red and marked with an asterisk (*) are due next week.” provides the same information but the color-, shape-, and size-dependent instructions are supplemented by searchable text indicators like an asterisk and Assignments text.

Multiple websites can be found to help test for color contrast concerns by Googling "color contrast checkers". As an alternative to web-based tools, a sample of the document may be printed using black and white or grayscale settings, then manually verifying the content can be read.