Dragon’s Fire on Opera
#fc4a14 on #816575
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
1.51:1
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 -14.5
Below Lc 15: the draft treats this as not text.
Light text on a darker ground — the negative sign is the polarity.
Colour difference
ΔE00 33.3
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#ffebe5 is the nearest colour of the same hue that passes AA on #816575, at 4.50:1. Only the lightness moved, and some chroma was given up to stay inside sRGB — which is the point: your colour stays recognisably your colour.
And to someone missing a cone
protanopia
Ratio 1.08:1, ΔE00 31.3.
deuteranopia
Ratio 1.73:1, ΔE00 34.8.
tritanopia
Ratio 2.49:1, ΔE00 24.6.
The weakest of the three is tritanopia, where the two are ΔE00 24.6 apart against 33.3 for a trichromat — still clearly two colours.
Both colours have pages of their own: Dragon’s Fire ·Opera · the same pair the other way round ·all pairs