About Color Contrast Checker How does it work?

Color Contrast Checker tool follows the Web Content Accessibility Guidelines (WCAG), which are a series of recommendations for making the web more accessible.
Regarding colors, the standard defines two levels of contrast ratio: AA (minimum contrast) and AAA (enhanced contrast).
The level AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (at least 18pt) or bold text.
The level AAA requires a contrast ratio of at least 7:1 for normal text and 4.5:1 for large text or bold text.

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