What contrast ratio does Standard 5568 require?

For normal text, WCAG 2.0 AA requires at least 4.5:1 against the background. Large text can meet 3:1. UI components and graphical objects that convey meaning also need sufficient contrast.

Is light gray text on white ever okay?

Often no. Many brand palettes use muted grays that fall below 4.5:1. Measure instead of guessing from a screenshot.

Does dark mode fix contrast automatically?

No. Dark themes can fail too, especially pale text on dark gray or brand colors on dark backgrounds.

Color contrast on websites, the AA numbers that actually matter

Visitors with low vision, older users, and people outdoors on a bright phone screen all depend on readable contrast. Design teams often ship light gray body text that looks refined on a calibrated monitor and fails the standard for real readers.

The numbers that matter

Normal text: at least 4.5:1
Large text (roughly 18pt regular or 14pt bold and up): at least 3:1
Icons and UI boundaries that carry meaning: aim for 3:1 against adjacent colors

Where sites fail

Placeholder text in forms
Footer links in light gray
Disabled-looking buttons that are actually active
Text over photos without a solid scrim
Error messages in pale red on white

How to check without a full audit

Use a contrast checker on the real CSS colors, not a compressed screenshot. Spot-check headings, body, links, buttons, and form labels on mobile and desktop.

Fix patterns that keep the brand

Darken body text one or two steps, raise link underline contrast, and put a solid or semi-solid panel behind hero copy instead of thin text on busy images.