many-coloured vs polychromic

many-coloured

adj
  • Composed of a great number of different colours; multicoloured; variegated. 

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