Contrast (Enhanced)

Understanding WCAG2.0

Strict criteria for 1.4.3. In 1.4.3 I was requesting a 3:1 contrast ratio, but even bigger letters require a contrast ratio of 4.5:1.

Principle Perceivable Information and user interface components must be presentable to users in ways they can perceive.
Guideline Distinguishable Make it easier for users to see and hear content including separating foreground from background.
Criterion Contrast (Enhanced)
(1.4.6 AAA)
For visual presentation of text and character images, there is a contrast ratio of at least 7: 1.

URL of Techniques for WCAG 2.0