The quick brown fox jumps.
Perceptual contrast decides whether your interface is readable — not just whether it passes a checkbox. APCA models how the human eye actually reads text on screens.
Small print at 14px regular weight is where most palettes quietly fail their users.
oklch(97.0% 0.02 264) on oklch(32.0% 0.13 264)
APCA Lc
95
Any text
WCAG 2.2
11.9
AAA · ratio
Foreground
97%
0.020
264°
Background
32%
0.130
264°
Role contrast matrix
| Primary | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Secondary | |||||||||
| Tertiary | |||||||||
| Neutral | |||||||||
| Success | |||||||||
| Warning | |||||||||
| Danger | |||||||||
| White | |||||||||
| Black |
Roles use their 500 step. Pairs on the diagonal (a colour on itself) are unusable by definition. Aim for Lc 75+ for body copy — click any cell for a suggested fix.