Difference between In black and In the black

in black—

1. wearing black clothes:

• A gentleman in black proceeded to call over the names of the jury.

2. wearing mourning clothes:

• Mrs. Smith is in black, I see. Whom has she lost?

3. executed or finished in black color:

• The table is very ornamental … the legs being of iron finished in black and gold.

Note: The expression does not correlate in meaning with the phrase in a black mood—irritable, angry, or depressed:

• We often talk about being in a black mood, feeling blue, going red with anger and green with envy.

in the black—(coll.) in a sound financial position; making a profit:

• We toyed with bankruptcy for a while, but now we’re in the black.