Color contrast answer

Does #0ea5e9 work on #ffffff?

#0ea5e9 text on a #ffffff background has a contrast ratio of 2.77:1, so it fails common WCAG contrast thresholds for text.

Sample text

Readable UI preview

Reversed pair

Check both directions in Blobb.

Open this page with JavaScript enabled to edit the colors, tune the pair, and compare it against a full palette.