Some food coloring (3)
I believe the answer is:
dye
'some food coloring' 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 "Colourant" , "Colouring liquid" , "Colour or stain something" , "Colouring material" , "Liquid used to change colour of clothes" .)