chromatism

from WordNet (r) 3.0 (2006)

chromatism
    n 1: hallucinatory perception of colored lights
    2: abnormal pigmentation

from The Collaborative International Dictionary of English v.0.48

Chromatism \Chro"ma*tism\, n. [Gr. ? a coloring.]
   [1913 Webster]
   1. (Optics) The state of being colored, as in the case of
      images formed by a lens.
      [1913 Webster]

   2. (Bot.) An abnormal coloring of plants.
      [1913 Webster]