The Collaborative International Dictionary of English v.0.48:

Polychromic \Pol`y*chro"mic\, a. [Poly- + (sense 1) Gr. ?, or
   (sense 2) chromic.]
   1. Polychromatic.
      [1913 Webster]

   2. (Chem.) Pertaining to, or designating, any one of several
      acids (known only in their salts) which contain more than
      one atom of chromium.
      [1913 Webster]

WordNet (r) 3.0 (2006):

polychromic
    adj 1: having or exhibiting many colors [syn: polychromatic,
           polychrome, polychromic]