polychromatic vs polychromic

polychromatic

adj
  • Showing a variety, or a change, of colours; having many colours; multicoloured. 

  • Composed of more than one wavelength. 

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