polychromic vs rainbowed

polychromic

adj
  • Polychromatic; many-coloured. 

  • Pertaining to, or designating, any one of several acids (known only in their salts) which contain more than one atom of chromium. 

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 polychromic and rainbowed occurred in a corpus of books? (source: Google Ngram Viewer )