black as night

(as) black as night

Very dark or black in color. A: "I can't believe that Grandma's hair used to be black as night." B: "Well, sure—you've only ever known her with gray hair."
See also: black, night

black as night

Also, black as coal or pitch . Totally black; also, very dark. For example, The well was black as night, or She had eyes that were black as coal. These similes have survived while others-black as ink, a raven, thunder, hell, the devil, my hat, the minister's coat, the ace of spades-are seldom if ever heard today. Of the current objects of comparison, pitch may be the oldest, so used in Homer's Iliad (c. 850 b.c.), and coal is mentioned in a Saxon manuscript from a.d. 1000. John Milton used black as night in Paradise Lost (1667).
See also: black, night
References in classic literature ?
But once more her scheme was doomed to failure, for hardly had she gone a yard from the church than both it and the monk disappeared, and she found herself in a wood black as night, and full of wolves and bears and wild animals of all sorts and descriptions.