A tetramorphic system was discovered in a diketopyrrolopyrrole dye (3,6-bis(4-chlorophenyl)-2-propyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione), with thermosalient effects during thermal phase transitions. Two polymorphs, the red and orange forms, were obtained using liquid-liquid and liquid-gas...