Web Accessibility Wednesday: Conveying Information Using Color Alone

This is part of a continuing series of web accessibility tips for IT personnel, web managers and web development groups. These tips can be used to review current website accessibility and to utilize in developing new websites with the hope of improving web accessibility for everyone.

Avoid using color or other stylistic differences as the only means of conveying information or meaning. Blind users do not care about the color, font size, or styling of text, so long as the visual aspects of that text are not used to convey content. Screen readers generally do not present stylistic information to the end user. Users with certain types of color deficiencies (color blindness) may not be able to differentiate certain color combinations. Users with low vision may override page colors. Each of these may have difficulty differentiating content based on color alone. The following relies on color to convey information:
The green mushrooms listed here are OK to eat. The red mushrooms will kill you.
 Amanita
 Chanterelle
 Porcini
 Shitake
 Tylopilus
This can be made accessible by simply creating two lists - one for mushrooms that OK to eat and one for mushrooms that will kill you.