We've upgraded our Accessibility validation servers to the latest version of axe-core, 4.4, which fixes some bugs and introduces an upgraded version of the contrast checker, so you may want to re-check your sites to get the most up-to-date results.
Enhanced contrast check
The new color contrast enhanced rule in Axe Core 4.4 checks that text elements have sufficient contrast between text in the foreground and background colors behind it in accordance with WCAG 2 AAA contrast ratio thresholds.
Success criterion: Ensure color contrast of at least 7:1 for small text or 4.5:1 for large text, even if text is part of an image. Large text has been defined in the requirements as 18pt (24 CSS pixels) or 14pt bold (19 CSS pixels).
Check out the 4.4 release notes.
Current accessibility ruleset
Check out the full list of accessibility rules that are being checked currently by our web crawlerAccessibility rules checked by Rocket Validator