Input fields and data entry elements maintain a contrast ratio of at least 3:1 against their background in all states.
Insufficient options field contrast:
This select dropdown has a border color with insufficient contrast (1.6:1) against its background:
Note: Possible to automatically test. This can be achieved by programmatically retrieving the current border-color (i.e. CSS color property, or otherwise) of an element and verifying that it has sufficient contrast against its background. However, a human tester or AI is most likely needed to confirm full visibility.