Wild Thing on Dragon’s Fire
#654243 on #fc4a14
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
2.54:1
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 27.4
Clears Lc 15 — disabled or purely decorative text, which is not meant to be read.
Dark text on a lighter ground.
Colour difference
ΔE00 35.0
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#3b1b1d is the nearest colour of the same hue that passes AA on #fc4a14, 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 1.85:1, ΔE00 25.5.
deuteranopia
Ratio 2.87:1, ΔE00 36.7.
tritanopia
Ratio 3.90:1, ΔE00 38.7.
The weakest of the three is protanopia, where the two are ΔE00 25.5 apart against 35.0 for a trichromat — still clearly two colours.
Both colours have pages of their own: Wild Thing ·Dragon’s Fire · the same pair the other way round ·all pairs