Source : Webster's Revised Unabridged Dictionary (1913)

Colorist \Col"or*ist\, n. [Cf. F. coloriste.]
   One who colors; an artist who excels in the use of colors;
   one to whom coloring is of prime importance.

         Titian, Paul Veronese, Van Dyck, and the rest of the
         good colorists.                          --Dryden.

Source : WordNet®

colorist
     n : a painter able to achieve special effects with color