Master Chief on Flirt
#507d2a on #7a2e4d
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
1.85:1
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 -14.8
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 55.8
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#94c571 is the nearest colour of the same hue that passes AA on #7a2e4d, 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 2.33:1, ΔE00 39.1.
deuteranopia
Ratio 1.65:1, ΔE00 22.7.
tritanopia
Ratio 1.40:1, ΔE00 50.0.
The weakest of the three is deuteranopia, where the two are ΔE00 22.7 apart against 55.8 for a trichromat — still clearly two colours.
Both colours have pages of their own: Master Chief ·Flirt · the same pair the other way round ·all pairs