Cover of Night on Shadow Play
#494e4f on #2d1403
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
2.05:1
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 -11.5
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 24.4
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#7e8384 is the nearest colour of the same hue that passes AA on #2d1403, 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 2.14:1, ΔE00 20.1.
deuteranopia
Ratio 2.00:1, ΔE00 20.6.
tritanopia
Ratio 1.90:1, ΔE00 28.0.
The weakest of the three is protanopia, where the two are ΔE00 20.1 apart against 24.4 for a trichromat — still clearly two colours.
Both colours have pages of their own: Cover of Night ·Shadow Play · the same pair the other way round ·all pairs