polychromate vs rainbowed

polychromate

adj
  • Composed of many colours 

noun
  • A salt or ion composed of multiple chromate groups 

rainbowed

adj
  • Resembling, involving, or illuminated with a rainbow; patterned with the colours of the rainbow. 

  • Made up of several races or ethnicities; rainbow. 

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