Any of a few steady, light-fast, blue or green organic pigments based on the fundamental mixture (C6H4C2N)4N4 and used in enamels, printing inks, linoleum, and plastics.
some of a family of macrocyclic compounds having a structure like porphyrin; they have been blue/green pigments which can be used in plastic materials and enamels
How would you define phthalocyanine?