Intrigue Red on Flirt
#b24648 on #7a2e4d
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
1.66:1
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 -12.1
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 18.0
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#ff9c99 is the nearest colour of the same hue that passes AA on #7a2e4d, 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 1.54:1, ΔE00 21.6.
deuteranopia
Ratio 1.71:1, ΔE00 20.3.
tritanopia
Ratio 1.86:1, ΔE00 17.3.
The weakest of the three is tritanopia, where the two are ΔE00 17.3 apart against 18.0 for a trichromat — still clearly two colours.
Both colours have pages of their own: Intrigue Red ·Flirt · the same pair the other way round ·all pairs