Colorants for Skin Care Products Cosmenyl Blue A4R Cosmenyl Blue A4R is a pigment dispersion of approx. 38% pigment and is based on anionic dispersing and wetting agents and glycerine. The Colour Index of the basic pigment is Pigment Blue 15:1. Cosmenyl Blue A4R is recommended for the coloration of personal care products, esp. soap bars and ...