The Color Contrast category contains criteria that determine how easily a user can read and understand the content of your app with respect to color. Color blindness is one of the most common disabilities, so ensuring that color contrast is accessible is a top priority.
Color Contrast accessibility criteria include:
The goal of this testing category is to ensure that a user can read and interact with the contents of your app regardless of how well they can perceive differences in color, if at all. Color (such as green for good and red for bad) shouldn’t be the only means of recognizing the status of something and should be accompanied by text and/or icons to provide extra context. The colors of foreground text against the background as well as the color of interactive elements (or non-text elements) such as buttons, links, and icons should all meet the minimum WCAG requirements for contrast ratios (4.5:1 ratio for foreground text against the background and 3:1 ratio for non-text elements).