Brand · the refusal
The check runs at the moment of choosing, not at save. It never says "fails a contrast standard" — it says what goes wrong, shows it, and hands over two colours that work. He was never shown a standards code, never shown a failing ratio, and never left without a colour.
1 · It's hard to read. White writing on this green is too faint for a phone in daylight — and your buttons carry white words all over the app.
2 · It turns into another colour the app already uses. Roughly one man in twelve can't tell red from green. To them your green becomes this brownish-gold — the same mark the app uses for "waiting on you".
Left to right: your green, how it reads to them, and the mark the app already uses. Two things that mean different things would look like one thing.
"You tried a green that turns into the waiting mark for people who cannot tell red from green. Nothing changed." — see the record.
The refusal itself is not signalled by red. It is a heading, two numbered sentences and a picture. A refusal that relies on a colour to be understood has already failed the person it exists to protect — and the person it would confuse is exactly the person who cannot tell you it is confusing them.
What the check actually tests: whether you can read white and dark text on the colour at the sizes the app really uses, in both the light and the dark theme; whether it survives both common forms of red/green colour blindness without collapsing into a mark the app already uses; and whether it is still itself against the app's own greys. Every refusal carries a way forward — the nearest colour of theirs that passes, plus one that is unambiguously safe.
He took the deeper green. It is the colour every screen in this preview is wearing. The working version of this check measures it live rather than drawing it.