Hair salon stock (3)
I believe the answer is:
dye
'hair salon stock' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dye that I've seen before include "Colour by dipping in liquid" , "Pigment" , "Colouring liquid" , "Hair colouring" , "Colour or stain something" .)