Uniform colloidal pigment dispersions of narrow size distribution were obtained by interacting aqueous solutions of D&C Red #6 dye and BaCl2. The original particles were elongated in shape but the anisometry could be altered by input of ultrasonic energy. The addition of an anionic surfactant caused a decrease of the average pigment size to ∼ 40 nm. The so prepared colored dispersions showed 100% transparency, which is considerable higher than the commercial Ba lake of the same dye.