black and white
black and white {n. phr.}
1. Print or writing; words on paper, not spoken; exact written or printed form.
He insisted on having the agreement down in black and white.
Mrs. Jones would not believe the news, so Mr. Jones showed her the article in the newspaper and said, "There it is in black and white."
2. The different shades of black and white of a simple picture, rather than other colors.
He showed us snapshots in black and white.
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Source: A Dictionary of American Idioms