Does APCA replace WCAG for legal compliance?

Not usually. Many orgs still require WCAG 2.x ratios. Use WCAG for audits; use APCA to improve real readability, especially on dark UI.

What Lc should I aim for?

It depends on size and weight. Body text typically needs a higher Lc than large display type. Always verify on the real type sample in Contrast Checker.

Why do dark UIs fail ‘feel’ but pass WCAG?

WCAG is polarity-blind. APCA accounts for light-on-dark vs dark-on-light, which often explains the gap you feel on charcoal surfaces.

WCAG vs APCA Contrast — Which to Use for UI Type

WCAG vs APCA

When to use WCAG 2.1 contrast ratios vs APCA Lc for body text and UI. Practical guidance with Colorise Pro’s live contrast checker.

WCAG 2.1 ratios

WCAG contrast is a relative luminance ratio (for example 4.5:1 for normal text, 3:1 for large text). It is the compliance baseline for many teams and audits — Colorise Pro reports it clearly next to live type.

APCA Lc

APCA models perceived contrast with polarity awareness (light-on-dark vs dark-on-light). Lc values help when WCAG looks like a “pass” but type still feels weak — a common issue on dark dashboards and dense tables.

Practical rule

Ship against WCAG when you need checklist compliance.
Tune readability with APCA on real type sizes and weights.
Always judge on samples — the Contrast Checker shows both on live UI text, with an Auto-Fix path when a pair fails.

Workflow that sticks

Lock brand colors in OKLCH (Studio or Picker).
Test critical pairs: body, captions, buttons, borders.
Prefer raising L contrast before blasting chroma.
Re-export tokens only after both WCAG and APCA look honest.

Try it

Open the Contrast Checker, set foreground and background, and compare WCAG ratio next to APCA Lc before you lock a brand pair. From a palette, use Continue in → Contrast for a one-click handoff.

FAQ

Does APCA replace WCAG for legal compliance?: Not usually. Many orgs still require WCAG 2.x ratios. Use WCAG for audits; use APCA to improve real readability, especially on dark UI.
What Lc should I aim for?: It depends on size and weight. Body text typically needs a higher Lc than large display type. Always verify on the real type sample in Contrast Checker.
Why do dark UIs fail ‘feel’ but pass WCAG?: WCAG is polarity-blind. APCA accounts for light-on-dark vs dark-on-light, which often explains the gap you feel on charcoal surfaces.