Dragon’s Fire on Panorama
#fc4a14 on #327a88
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
1.43:1
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 -12.7
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 50.0
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#fff2ef is the nearest colour of the same hue that passes AA on #327a88, 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 1.11:1, ΔE00 34.7.
deuteranopia
Ratio 1.76:1, ΔE00 46.6.
tritanopia
Ratio 2.52:1, ΔE00 73.6.
The weakest of the three is protanopia, where the two are ΔE00 34.7 apart against 50.0 for a trichromat — still clearly two colours.
Both colours have pages of their own: Dragon’s Fire ·Panorama · the same pair the other way round ·all pairs