Carlos Cruz-Diez Physichromie No. 965 (1977) mixed media 40 x 60" Impressed by Soto's work, Cruz-Diez began to study the physical properties of color.  In 1959 he began his series Fisicromias, panels transversed by narrow strips that modulate the color of the paintings, depending on the movement of the viewer and the quality of the ambient light.  They are based on Itten's theory of the simultaneous perception of different colors.  Seeking to produce a dynamic effect on the eye of the spectator, the artist made use of a variety of devices: linear shock, fusion of tonalities, parallel placement of thin colored plates so as to create the effect of a moving image, and other types of optical illusion.  He finally evolved a technique employing what he specifically termed "additive color," leading to the production of "chromo-interferences" or chromatic kineticism.  Cruz-Diez is concerned primarily with the autonomy of color and its development in space.  An experimenter with divisionism- like Seurat a hundred years ago and Agam today- Cruz-Diez works in the line of investigative art, more particularly in the fields of kinetics and optical illusion.