Prussian blue

noun

1. a moderate to deep greenish blue.

2. one of the iron blues, a dark-blue, crystalline, water-insoluble pigment, Fe 4 [Fe(CN) 6 ] 3 , produced by reacting ferrocyanic acid or a ferrocyanide with a ferric compound: used in painting, fabric printing, and laundry bluing.

Prussian blue

noun

1. any of a number of blue pigments containing ferrocyanide or ferricyanide complexes

2. 1. the blue or deep greenish-blue colour of this pigment

   2. ( as adjective )

      a Prussian-blue carpet

Word History and Origins

Origin of Prussian blue¹

1715–25; translation of French bleu de Prusse, so called because it was discovered and first reported in Berlin, capital of Prussia