Crepuscular on Cyantific
#e7dcce on #77c9c2
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
1.42:1
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 -19.4
Clears Lc 15 — disabled or purely decorative text, which is not meant to be read.
Light text on a darker ground — the negative sign is the polarity.
Colour difference
ΔE00 27.0
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#534a3f is the nearest colour of the same hue that passes AA on #77c9c2, 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 1.30:1, ΔE00 9.2.
deuteranopia
Ratio 1.49:1, ΔE00 17.9.
tritanopia
Ratio 1.62:1, ΔE00 49.7.
The weakest of the three is protanopia, where the two are ΔE00 9.2 apart against 27.0 for a trichromat — still two colours, but a closer call than it looks to you.
Both colours have pages of their own: Crepuscular ·Cyantific · the same pair the other way round ·all pairs