Blue dye (6)
'blue dye' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for indigo that I've seen before include "type of dye" , "Deep dark blue" , "Ellington's Mood" , "I of ROYGBIV" , "Deep-blue dye or colour" .)
'blue dye' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for anil that I've seen before include "It produces dye" , "Indian man" , "Colouring" , "Indigo (plant or dye)" , "Shrub yielding indigo" .)