pitch black
Completely or extremely black. ("Pitch" is a viscous black resin produced from coal or wood tar.) The stars were covered by clouds, and there were no lights for miles, so it was pitch black all around our campsite after we extinguished the fire. She said she wanted to paint her room pitch black.
pitch black
very black; as black as pitch. The hearse was pitch black. The bandit rode on a pitch black horse and wore black clothing.