coal black vs inky

coal black

adj
  • Of an intensely black colour, like that of coal. 

noun
  • A black colour, like that of coal; charcoal. 

inky

adj
  • Of the colour of ink, especially black ink; dark. 

  • Spattered or stained with ink. 

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