Midnight Edition on Abyssal Waters
#0c121b on #005765
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
2.28:1
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 15.3
Clears Lc 15 — disabled or purely decorative text, which is not meant to be read.
Dark text on a lighter ground.
Colour difference
ΔE00 25.2
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#b8c0cd is the nearest colour of the same hue that passes AA on #005765, 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 2.45:1, ΔE00 21.1.
deuteranopia
Ratio 2.19:1, ΔE00 19.6.
tritanopia
Ratio 2.24:1, ΔE00 24.6.
The weakest of the three is deuteranopia, where the two are ΔE00 19.6 apart against 25.2 for a trichromat — still clearly two colours.
Both colours have pages of their own: Midnight Edition ·Abyssal Waters · the same pair the other way round ·all pairs