Abstract: Apparatus for a color coded visualization of ultrasonic field patterns resenting differences in acoustical impedance within a solid or liquid body. Colored ultrasonic images are obtained in response to a multifrequency interrogation of a test specimen by a multifrequency energization of an ultrasonic transducer with indications of characteristic color being obtained at the loci of discontinuities or inhomogeneities in the specimen (solid and/or liquid) being examined. Colored images are provided by an electronic superposition of images on a color television monitor subsequent to the images being color encoded in accordance with at least two, but preferably the three primary colors of red, green and blue.