cornflower blue vs indigo bunting

cornflower blue

noun

  • A bright blue color, with a tint of purple. 

adj

  • Of a bright blue color, with a tint of purple 

indigo bunting

noun

  • A blue bunting of North America, Passerina cyanea. 

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