Interactive UI elements must have a contrast ratio of at least 3:1 against their background in all states.
Insufficient checkbox contrast:
These checkboxes have an insufficient contrast ratio against the background:
Note: Possible to automatically test. This violation can be detected by querying all controls/interactive elements (e.g., buttons), programmatically retrieving their color attributes (e.g., from the CSS stylesheet), along with the background-color attributes of their background elements, and verifying that an appropriate contrast ratio exists between them.
If the color of an element or the background-color of the parent element cannot be determined, a human tester or AI is required to visually check the contrast ratio of an input element against its background.