Nickel on Ethereal Espresso
#929292 on #3e2723
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
4.44:1
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 -39.1
Clears Lc 30 — the floor: below this the draft considers text not readable at any size.
Light text on a darker ground — the negative sign is the polarity.
Colour difference
ΔE00 38.9
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#939393 is the nearest colour of the same hue that passes AA on #3e2723, 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 4.63:1, ΔE00 37.9.
deuteranopia
Ratio 4.35:1, ΔE00 37.1.
tritanopia
Ratio 4.14:1, ΔE00 39.5.
The weakest of the three is deuteranopia, where the two are ΔE00 37.1 apart against 38.9 for a trichromat — still clearly two colours.
Both colours have pages of their own: Nickel ·Ethereal Espresso · the same pair the other way round ·all pairs