| any of the class of blue pigments having a high tinting strength and ranging in shade and in coloring properties from reddish blue to jet blue: used chiefly in the manufacture of paints and printing inks. |
| iron blue n. Any of various light-resistant and heat-resistant, semitransparent blue pigments of powerful tinctorial strength, used chiefly in permanent industrial finishes, printing inks, and artists' colors. Also called Prussian blue. |