Peel off fine red pigment (5)
I believe the answer is:
flake
'peel off' is the definition.
(I know that peel off can be written as flake)
'fine red pigment' is the wordplay.
'fine' becomes 'f' (abbreviation in pencil classifications).
'red pigment' becomes 'lake' (I've seen this in another clue).
'f'+'lake'='FLAKE'
(Other definitions for flake that I've seen before include "Piece of falling snow" , "Sliver" , "Snow crystal" , "bit of snow" , "Small chipping" .)