Coloration (12)
I believe the answer is:
pigmentation
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">coloration</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that pigmentation is a type of coloration)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for pigmentation that I've seen before include "Natural colouring" , "For example, madder" .)