Sheared isotactic polypropylene (iPP) forms a special crystalline assembly called branched shish kebab. The effects of two colorants, Cu-phthalocyanine and ultramarine blue, on the branched shish-kebab structure have been investigated by using synchrotron wide-angle x-ray scattering. The effects of the colorants on the morphological distributions of iPP are well constructed through the shear field or temperature gradient, including crystallinity, molecular orientation, fraction of lamellae, and thickness of crystalline lamellae. It is found that the Cu-phthalocyanine can significantly affect the morphological development of sheared iPP but the ultramarine blue cannot. In the presence of Cu-phthalocyanine, the degree of crystallinity is increased, the molecular orientation is enhanced, the more a*-axis-oriented components form, and the crystalline lamellae are thickened. [ABSTRACT FROM AUTHOR]