Secret Path on Cyantific
#737054 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
2.62:1
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 36.0
Clears Lc 30 — the floor: below this the draft considers text not readable at any size.
Dark text on a lighter ground.
Colour difference
ΔE00 33.8
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#4f4c32 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 2.84:1, ΔE00 29.4.
deuteranopia
Ratio 2.50:1, ΔE00 31.2.
tritanopia
Ratio 2.30:1, ΔE00 49.7.
The weakest of the three is protanopia, where the two are ΔE00 29.4 apart against 33.8 for a trichromat — still clearly two colours.
Both colours have pages of their own: Secret Path ·Cyantific · the same pair the other way round ·all pairs