Black Box on Florida’s Alligator
#0f282f on #664422
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
1.77:1
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 10.5
Below Lc 15: the draft treats this as not text.
Dark text on a lighter ground.
Colour difference
ΔE00 31.3
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#a3bfc8 is the nearest colour of the same hue that passes AA on #664422, 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
Ratio 1.61:1, ΔE00 25.0.
deuteranopia
Ratio 1.86:1, ΔE00 30.7.
tritanopia
Ratio 2.04:1, ΔE00 50.3.
The weakest of the three is protanopia, where the two are ΔE00 25.0 apart against 31.3 for a trichromat — still clearly two colours.
Both colours have pages of their own: Black Box ·Florida’s Alligator · the same pair the other way round ·all pairs