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]WordNet (r) 3.0 (2006):
chromatism n 1: hallucinatory perception of colored lights 2: abnormal pigmentation