Master Chief on Super Pink
#507d2a on #ce6ba6
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
1.46:1
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 11.2
Below Lc 15: the draft treats this as not text.
Dark text on a lighter ground.
Colour difference
ΔE00 62.5
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#152c00 is the nearest colour of the same hue that passes AA on #ce6ba6, 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 1.15:1, ΔE00 42.8.
deuteranopia
Ratio 1.64:1, ΔE00 34.5.
tritanopia
Ratio 1.89:1, ΔE00 58.2.
The weakest of the three is deuteranopia, where the two are ΔE00 34.5 apart against 62.5 for a trichromat — still clearly two colours.
Both colours have pages of their own: Master Chief ·Super Pink · the same pair the other way round ·all pairs