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Color Contrast Related to Links
For usability and accessibility, links should be underlined by default. Otherwise, link text must have at least 3:1 contrast with surrounding body text, and must present a non-color indicator (typically underline) on mouse hover and keyboard focus.
There should be a contrast ratio of at least 4.5.1 between link text and background color. This applies to regular body text (or 3:1 for large text) .
There must be a 3.1 contrast ratio between link text and the surrounding text.
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