Color Contrast Standards: WCAG AA vs AAA

Color contrast measures the luminance ratio between foreground text (or interactive icons) and the background surface. Low contrast creates severe barriers for people with low vision, color vision deficiencies, or users viewing screens in bright sunlight.

Under WCAG 2.1 Level AA (the global industry standard):

• Normal Text (< 18pt regular or < 14pt bold): Minimum contrast ratio of 4.5:1.
• Large Text ($\ge$ 18pt regular or $\ge$ 14pt bold): Minimum contrast ratio of 3.0:1.
• Non-Text UI Elements & Graphical Objects: Active component boundaries, form input borders, and essential icons require at least 3.0:1.
• WCAG AAA (Enhanced Standard): Requires 7.0:1 for normal text and 4.5:1 for large text.