WCAG (แนวทางความสามารถในการเข้าถึงเนื้อหาเว็บ)

WCAG provides three conformance levels: A (minimum), AA (standard), and AAA (enhanced). For color, the key success criteria are 1.4.3 (Contrast Minimum, level AA) requiring 4.5:1 for normal text and 3:1 for large text, and 1.4.6 (Enhanced Contrast, level AAA) requiring 7:1 for normal text and 4.5:1 for large text. WCAG 2.1 (current) also requires that color is not the only means of conveying information (1.4.1). Most legal accessibility requirements in the US (Section 508), EU (EN 301 549), and other jurisdictions reference WCAG AA as the minimum standard.