Abstract: An ?-diketopyrrolopyrrole pigment characterized by giving an X-ray diffraction spectrum in which the ratio of the peak density (I020) for plane index (020) to the peak intensity (I?141) for plane index (?141), I020/I?141 is 0.40 or lower and the ratio of the peak intensity (I?141) for plane index (?141) to the peak intensity (I111) for plane index (111), I?141/I111 is 1.28 or lower. Also provided are: a coloring composition containing this pigment; and a red film formed with this coloring composition. In a color filter formed with ?-diketopyrrolopyrrole pigment, which has that property, the red filter segments have a high contrast ratio and a small absolute value of birefringence. Consequently, a color liquid-crystal display or the like having small viewing-angle dependence and showing excellent display characteristics can be produced.

Abstract: A process for producing dichlorodiketopyrrolopyrrole pigment of the ? modification, which comprises wet milling crude dichlorodiketopyrrolopyrrole pigment wherein an ? modification and a ? modification coexist in the presence of a milling agent and a wetting agent, dichlorodiketopyrrolopyrrole pigment of the ? modification obtained the process and a color composition which contains the pigment and a pigment carrier.

Abstract: A process for producing dichlorodiketopyrrolopyrrole pigment of the ? modification, which comprises wet milling crude dichlorodiketopyrrolopyrrole pigment wherein an ? modification and a ? modification coexist in the presence of a milling agent and a wetting agent, dichlorodiketopyrrolopyrrole pigment of the ? modification obtained the process and a color composition which contains the pigment and a pigment carrier.