Master Sword Blue on God of Rain
#00ffee on #4466cc
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
4.12:1
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 -64.4
Clears Lc 60 — headlines and other larger text.
Light text on a darker ground — the negative sign is the polarity.
Colour difference
ΔE00 51.1
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#9ffff4 is the nearest colour of the same hue that passes AA on #4466cc, at 4.50:1. Only the lightness moved, and some chroma was given up to stay inside sRGB — which is the point: your colour stays recognisably your colour.
And to someone missing a cone
protanopia
Ratio 4.47:1, ΔE00 47.6.
deuteranopia
Ratio 3.91:1, ΔE00 39.6.
tritanopia
Ratio 2.98:1, ΔE00 31.4.
The weakest of the three is tritanopia, where the two are ΔE00 31.4 apart against 51.1 for a trichromat — still clearly two colours.
Both colours have pages of their own: Master Sword Blue ·God of Rain · the same pair the other way round ·all pairs