iso·chromatic \| ̷ ̷ ̷ ̷+\adjective Etymology: International Scientific Vocabulary is- + chromatic 1. a.: of or corresponding to constant color < the isochromatic variation of refractive index with density for a given wavelength > b.: connecting points of the same color c.: coincident with a line of equal stress in a photoelastic stress pattern 2.: orthochromatic 3.of cells or tissues: having the same color; specifically: staining similarly with like dyes