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]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "coloration":
   achromatism, allegory, allusion, arcane meaning, assumption, cast,
   chromatism, chromism, color, color balance, color harmony,
   color printing, color scheme, coloring, complexion, connotation,
   decorator color, dyeing, emblazonry, hint, hue, illumination,
   implication, implied meaning, import, inference, innuendo,
   intimation, ironic suggestion, key, lithography, meaning,
   metaphorical sense, natural color, nuance, occult meaning,
   overtone, pallor, pigmentation, presumption, presupposition, shade,
   skin color, staining, subsense, subsidiary sense, suggestion,
   supposition, symbolism, tinct, tinction, tincture, tinge, tinging,
   tint, tinting, tone, touch, undercolor, undercurrent, undermeaning,
   undertone