multicolor vs polychromic

multicolor

adj
  • Having, resembling, or pertaining to many colors. 

noun
  • A display of many colors. 

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