monochromatic vs monocolour

monochromatic

adj
  • Having only one color, represented by differing hues and tints. For example shades in a black and white television. 

  • Perceptive of only one color; unable to distinguish colors; total color blindness. 

  • Plain, dull, lifeless. 

monocolour

adj
  • Australia, Canada, Ireland, New Zealand, and UK standard spelling of monocolor. 

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