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.
Origin of iron blue
First recorded in 1690–1700
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for iron blue
His bare head, with its clustered, red-brown hair, looked quite wonderful in the setting of golden leaves and iron-blue grapes.Shadows of Flames|Amelie Rives