murky vs pitch-black

murky

adj
  • Dark, dim, gloomy. 

  • Hard to see through, as a fog or mist. 

  • Cloudy, indistinct, obscure. 

  • Dishonest, shady. 

pitch-black

adj
  • Very dark; without light. 

How often have the words murky and pitch-black occurred in a corpus of books? (source: Google Ngram Viewer )