Pigmented polymer compositions and processes for preparing melt-processible polymer compositions contain a melt-processible polymer, surface treated organic pigment, typically titanium dioxide, and a polymer processing aid are described. The pigment is surface treated by contact with a silicon-containing compound, such as octyltriethoxysilane followed by contact with an organic compound such as isostearic acid or ethoxylated silicone. The pigmented polymer composition containing a polymer processing aid facilitates production of shaped articles with low melt fracture.