Castro on Out of the Blue
#44232f on #1199ee
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
4.46:1
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 41.1
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 53.5
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#43222e is the nearest colour of the same hue that passes AA on #1199ee, 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 5.21:1, ΔE00 45.6.
deuteranopia
Ratio 4.10:1, ΔE00 43.1.
tritanopia
Ratio 3.25:1, ΔE00 61.1.
The weakest of the three is deuteranopia, where the two are ΔE00 43.1 apart against 53.5 for a trichromat — still clearly two colours.
Both colours have pages of their own: Castro ·Out of the Blue · the same pair the other way round ·all pairs