polychromate vs polychromic

polychromate

adj
  • Composed of many colours 

noun
  • A salt or ion composed of multiple chromate groups 

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. 

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