Magic Carpet on Purple Climax
#9488be on #8800ff
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
1.87:1
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 -17.1
Clears Lc 15 — disabled or purely decorative text, which is not meant to be read.
Light text on a darker ground — the negative sign is the polarity.
Colour difference
ΔE00 27.3
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#e1daff is the nearest colour of the same hue that passes AA on #8800ff, at 4.50:1. Only the lightness moved, and some chroma was given up to stay inside sRGB — which is the point: your colour stays recognisably your colour.
And to someone missing a cone
protanopia
Ratio 2.17:1, ΔE00 28.7.
deuteranopia
Ratio 1.74:1, ΔE00 23.3.
tritanopia
Ratio 1.81:1, ΔE00 18.3.
The weakest of the three is tritanopia, where the two are ΔE00 18.3 apart against 27.3 for a trichromat — still clearly two colours.
Both colours have pages of their own: Magic Carpet ·Purple Climax · the same pair the other way round ·all pairs