On each web page, are the colours used in the user interface components or graphic element conveying information sufficiently contrasting (excluding special cases)?

Referência WCAG

3.3.1

On each web page, does the contrast ratio between the colours of a user interface component in its various states and the adjacent background colour satisfy one of these conditions (excluding special cases)?

The contrast ratio is at least 3:1.
A mechanism allows a contrast ratio of 3:1, at least.
3.3.2

On each web page, does the contrast ratio between the different colours making up a graphic element, when they are necessary for its understanding, and the adjacent background colour, meet one of these conditions (excluding special cases)?

The contrast ratio is at least 3:1.
A mechanism allows a contrast ratio of 3:1, at least.
3.3.3

On each web page, does the contrast ratio between the different adjacent colours of a graphic element, when they are necessary for its understanding, meet one of these conditions (excluding special cases)?

The contrast ratio is at least 3:1.
A mechanism allows a contrast ratio of at least 3:1.
3.3.4

In the mechanism for displaying a compliant contrast ratio, are the colours of the component or of its graphic element conveying information sufficiently contrasted?