Colouring pencil (6)
I believe the answer is:
crayon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">colouring pencil</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for crayon that I've seen before include "Drawing implement" , "Coloured rod" , "Stick to colour" , "Stick of coloured wax for drawing (6)" , "One colours with this" .)