grayscale vs monocoloured

grayscale

adj
  • Black and white, representing color with shades of gray. 

verb
  • To convert to grayscale. 

noun
  • A printed strip of graduated tones used to check exposure and development times. 

  • The use of black and white, representing color with shades of gray. 

monocoloured

adj
  • Of a single colour. 

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