Artist’s crayon (6)
I believe the answer is:
pastel
'artist's crayon' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for pastel that I've seen before include "Staple (anag)" , "Drawing crayon; light shade" , "Of a colour, subtle" , "Type of crayon" , "Pleats of a light colour" .)