THE COLOR BEHIND THE COLOR
Three layers.
One clear ratio.
Transparency changes what you see. Check text over a background over an opaque canvas, then inspect the effective colors and exact thresholds.
1. Set your layers
Hex 3/4/6/8, comma-separated rgb() or rgba(). RGB 0..255, alpha 0..1. No named, HSL, wide-gamut or percentage colors.
Pair results describe solid color contrast, not a full accessibility audit.
2. Read the result
A sentence at normal text size.
Large text, same colors.
Preview uses computed opaque effective colors, not actual font-edge antialiasing. Your display and browser affect appearance.
Large text: at least 18pt (24 CSS px), or 14pt bold (about 18.67 CSS px). Other fonts/scripts need equivalent sizing. Non-text 3:1 is only a numerical threshold check, not a component compliance verdict.
3. Compare a palette
2 to 12 named opaque colors. Rows are foreground, columns background. Pairs use unrounded numbers. Alpha colors belong in pair mode.
PASS means the pair meets normal-text AA 4.5:1 only. It does not certify a palette, page or design.