A technique for the identification of individual anisotropic grains in a heterogeneous and opaque material involves the observation of grain color in a reflecting light optical microscope. Such colors are generally characteristic of particular phases. We have studied the presence of color in many superconducting cuprates and found a strong correlation between color and the existence of superconductivity. The change in color from insulator to superconductor facilitates the selection of grains for microanalysis. Color variations in a Tl-Sr-Ca-Cu-O material are investigated using quantitative energy dispersive x-ray spect-roscopy. Cation concentrations are found not to correlate with the changes in color. This apparent lack of correlation of color with composition is discussed.