Color contrast requirements at mobile scale
WCAG contrast requirements apply equally to mobile and desktop, but small screen sizes compound the practical impact of low contrast. At small type sizes (11–13px, common for mobile labels, captions, and secondary text), low contrast is both harder to read and more likely to fail WCAG AA (4.5:1 for small text). Mobile designs that pass contrast at 16px body text can still have systematic contrast failures at smaller sizes. Mobile-specific audit practice: test every text style in your design system at its actual mobile size (not at 2× or 3× design tool zoom) and on a real device at standard brightness. The visual impact of a contrast failure is physically different on a 6-inch phone screen than on a 27-inch monitor — what looks passable on the large screen can be genuinely difficult to read on the small one.