The term Prussian blue refers to a particular blue pigment which is dark blue and made artificially. It is also called Berlin Blue and in painting, is also known as Parisian or Paris blue. Prussian blue is one among the first pigments made artificially. This blue pigment is used in paints, and it is the usual "blue" found in blueprints. Prussian blue is widely used in oil, watercolor, and dyeing.