Kelp on Vintage Bloom
#4d503c on #c0b0d0
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
4.10:1
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 47.2
Clears Lc 45 — large or heavy display text.
Dark text on a lighter ground.
Colour difference
ΔE00 47.9
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#474a36 is the nearest colour of the same hue that passes AA on #c0b0d0, 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 4.00:1, ΔE00 45.5.
deuteranopia
Ratio 4.15:1, ΔE00 45.5.
tritanopia
Ratio 4.12:1, ΔE00 40.1.
The weakest of the three is tritanopia, where the two are ΔE00 40.1 apart against 47.9 for a trichromat — still clearly two colours.
Both colours have pages of their own: Kelp ·Vintage Bloom · the same pair the other way round ·all pairs