Acoustic Brown on Cover of Night
#766b69 on #494e4f
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
1.64:1
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 -12.0
Below Lc 15: the draft treats this as not text.
Light text on a darker ground — the negative sign is the polarity.
Colour difference
ΔE00 15.2
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#c7bbb8 is the nearest colour of the same hue that passes AA on #494e4f, 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 1.60:1, ΔE00 11.4.
deuteranopia
Ratio 1.66:1, ΔE00 13.0.
tritanopia
Ratio 1.65:1, ΔE00 32.3.
The weakest of the three is protanopia, where the two are ΔE00 11.4 apart against 15.2 for a trichromat — still clearly two colours.
Both colours have pages of their own: Acoustic Brown ·Cover of Night · the same pair the other way round ·all pairs