black as pitch

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(as) black as pitch

Completely black; totally without light or color. The basement gives me the creeps, it's as black as pitch down there! A: "I can't believe that Grandma's hair used to be black as pitch." B: "Well, sure—you've only ever known her with gray hair." My hands were black as pitch after working on that filthy engine all day.

black as pitch

Totally dark, without any illumination. Distilling coal, peat, and other organic substances yield a very dark resinous residue called pitch (“pitch” and “tar” have became virtually synonymous). Anything that dark made a very good simile for “black.” The contemporary expression is “pitch black.” Those who chose to give the absence of light a theological cast would have said “black as sin,” while an imaginative Irish simile was “as black as the Earl of Hell's waistcoat.”