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.
- Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1;
- Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.
- Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.