Atlas Cedar on Black Box
#5ca0a7 on #0f282f
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
5.16:1
Passes AA for body text
Not AAA (7:1). Swapping the two colours gives the same number — the ratio does not know which is the text.
APCA
Lc -42.5
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 41.4
different colours
Above 10 — related only in the sense that both are colours.
Nothing to fix
This pair already clears 4.5:1, so #5ca0a7 can stay exactly as it is. Check another pair.
And to someone missing a cone
protanopia
Ratio 5.41:1, ΔE00 42.5.
deuteranopia
Ratio 5.02:1, ΔE00 39.5.
tritanopia
Ratio 4.96:1, ΔE00 40.1.
The weakest of the three is deuteranopia, where the two are ΔE00 39.5 apart against 41.4 for a trichromat — still clearly two colours.
Both colours have pages of their own: Atlas Cedar ·Black Box · the same pair the other way round ·all pairs