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).