WCAG 2.0 requires that the foreground and background colors have a 4.5:1 contrast ratio at Level AA and a 7:1 contrast ratio at Level AAA. You can use our contrast checker tool to determine what the ratio is between any foreground and background color.
WCAG 2.0 also requires (at Level A) that color not be used as the sole method of conveying content or distinguishing visual elements. They further define this requirement for links with Technique G183, which states, “Using a contrast ratio of 3:1 with surrounding text and providing additional visual cues on focus for links or controls where color alone is used to identify them.” This means that if you do not underline your links (or provide some other non-color designator for links), that the links must be sufficiently different in contrast from the surrounding text.
So if you combine these two requirements, in order to be Level AA conformant, your page must have all of the following:
- A 4.5:1 contrast between the non-link text color and the background.
- A 4.5:1 contrast between the link text color and the background.
- A 3:1 contrast between the link text color and the surrounding non-link text color.
In other words, your link color has to be significantly different from the background color AND the surrounding text color, which also has to be significantly different from the background color.
