The Collaborative International Dictionary of English v.0.48:

Coloration \Col`or*a"tion\, n.
   The act or art of coloring; the state of being colored.
   --Bacon.
   [1913 Webster]

         The females . . . resemble each other in their general
         type of coloration.                      --Darwin.
   [1913 Webster]

WordNet (r) 3.0 (2006):

coloration
    n 1: the timbre of a musical sound; "the recording fails to
         capture the true color of the original music" [syn:
         color, colour, coloration, colouration]
    2: appearance with regard to color; "her healthy coloration"
       [syn: coloration, colouration]
    3: choice and use of colors (as by an artist) [syn:
       coloration, colouration]