Flash in the Pan on Kelp
#ff9977 on #4d503c
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
3.98:1
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 -47.2
Clears Lc 45 — large or heavy display text.
Light text on a darker ground — the negative sign is the polarity.
Colour difference
ΔE00 47.8
different colours
Above 10 — related only in the sense that both are colours.
What the text colour has to become
#ffaa8e is the nearest colour of the same hue that passes AA on #4d503c, 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 3.39:1, ΔE00 35.5.
deuteranopia
Ratio 4.31:1, ΔE00 42.7.
tritanopia
Ratio 5.21:1, ΔE00 52.0.
The weakest of the three is protanopia, where the two are ΔE00 35.5 apart against 47.8 for a trichromat — still clearly two colours.
Both colours have pages of their own: Flash in the Pan ·Kelp · the same pair the other way round ·all pairs