Turn blue, maybe (3)
I believe the answer is:
dye
'turn blue maybe' 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" , "Colorant" , "Soluble substance for staining or colouring" , "Colour (fabrics)" , "Colouring agent" .)