In the black means having money left over rather than owing. Back in the black, firmly in the black, finish the year in the black.
It is the counterpart of in the red and comes from the same bookkeeping practice, since ordinary entries were made in black ink. A shop that trades all year to be in the black by Christmas is the origin of a famous name for the day.
1phrasein the blackHaving money left over rather than owing.
“After three difficult years, the café is finally in the black.”
in the black is a state.
From the accounting practice of entering positive figures in black ink.
From the standard accounting practice of using black ink, as opposed to red ink, to denote positive values, especially a net income.
Etymology from Wiktionary, CC BY-SA
Practised in Shopping & Money