cerulean vs deep blue

cerulean

adj

  • Sky-blue. 

noun

  • Any of various lycaenid butterflies of the genus Jamides. 

  • A greenish-blue color. 

deep blue

adj

  • An intense, relatively dark blue. 

noun

  • An intense, relative dark blue. 

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