midnight blue vs turquoise

midnight blue

adj

  • of a dark blue colour, almost black. 

noun

  • a dark blue colour, almost black. 

turquoise

adj

  • Having a pale greenish-blue colour. 

  • Made of turquoise (the gemstone). 

noun

  • A sky-blue, greenish-blue, or greenish-gray semi-precious gemstone. 

  • A pale greenish-blue colour, like that of the gemstone. 

  • turquoise 

How often have the words midnight blue and turquoise occurred in a corpus of books? (source: Google Ngram Viewer )