Florida’s Alligator on Kelp

#664422 on #4d503c

Body text at this size

And the smaller size most interfaces actually use for paragraphs — the size that decides whether a pair is usable.

Caption text, which almost nothing passes.

WCAG 2.1

1.05:1

Fails AA

Not AAA (7:1). Swapping the two colours gives the same number — the ratio does not know which is the text.

APCA

Lc 0.0

Below Lc 15: the draft treats this as not text.

Too close to call.

Colour difference

ΔE00 17.9

different colours

Above 10 — related only in the sense that both are colours.

What the text colour has to become

#dfb793 is the nearest colour of the same hue that passes AA on #4d503c, at 4.50:1. Only the lightness moved — which is the point: your colour stays recognisably your colour.

And to someone missing a cone

protanopia

Body text

Ratio 1.13:1, ΔE00 6.8.

deuteranopia

Body text

Ratio 1.01:1, ΔE00 8.8.

tritanopia

Body text

Ratio 1.09:1, ΔE00 18.8.

The weakest of the three is protanopia, where the two are ΔE00 6.8 apart against 17.9 for a trichromat — still two colours, but a closer call than it looks to you.

Both colours have pages of their own: Florida’s Alligator ·Kelp · the same pair the other way round ·all pairs