Prussian Blue (Hue)Color: Prussian Blue (Hue)Permanence: AAOpacity: OpaquePigment: PB29, PB15: 3, PBk7Pigment description: Silicate of Sodium and Aluminum with Sulfur, Copper Phthalocyanine , Nearly Pure Amorphous CarbonASTM Rating Ligthfastness: IPigment classification: MixtureColor Index Number: Viscosity range (mPa. s): 800 1. 500 Color IndexThe pigments used for artists colors are inorganic as well as organic. The inorganic pigments have been used since antiquity;