Memorial Black on Master Chief
#091101 on #507d2a
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
3.94:1
Large text only
Not AAA (7:1). Swapping the two colours gives the same number — the ratio does not know which is the text.
APCA
Lc 29.9
Clears Lc 15 — disabled or purely decorative text, which is not meant to be read.
Dark text on a lighter ground.
Colour difference
ΔE00 37.0
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#edfadf is the nearest colour of the same hue that passes AA on #507d2a, 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 4.17:1, ΔE00 37.8.
deuteranopia
Ratio 3.82:1, ΔE00 35.5.
tritanopia
Ratio 3.89:1, ΔE00 35.0.
The weakest of the three is tritanopia, where the two are ΔE00 35.0 apart against 37.0 for a trichromat — still clearly two colours.
Both colours have pages of their own: Memorial Black ·Master Chief · the same pair the other way round ·all pairs