The root produces a fine red colouring material, which has been used as a dye in the Mediterranean region since antiquity. The dyestuff in its roots is insoluble in water but can be extracted using alcohol or other organic solvents such as oils. In alkaline environments, alkanet dye is blue; in the presence of acids it gradually changes to crimson. The colouring agent in
A. tinctoria root has been chemically isolated and named
alkannin. In Australia, alkannin is approved for use as a food colouring; in the European Union, it is called E103 but its approval for use has been withdrawn. It has been used as colorant for products such as
lipstick. In English in the late medieval era, the name
alkanet meant
A. tinctoria. In the centuries since then, the name has come to be used informally for some other plants related to it. ==References==