Colour Contrast

The old Accessibility Evaluation and Repair Tools (AERT) suggested algorithm for determining colour contrast now directs here. The AERT algorithm was never a recommendation, and WCAG 2.0's luminosity contrast algorithm is recommended instead.

Success Criterion 1.4.3 of WCAG 2.0 requires the visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following:

Analyse Luminosity Contrast Ratio