Lacking pigment (6)
I believe the answer is:
albino
'lacking pigment' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for albino that I've seen before include "Person or animal with no colouring pigment" , "Person lacking pigment" , "Abnormally white creature" , "pale thing" , "Unpigmented creature" .)