Fluid concentrates, colorants and coating compositions contain solid pigment particles dispersed in a nonvolatilizing, reactive liquid diluent having a viscosity less than 1,000 cps and containing at least one molecular species having at least three reactive unsaturated sites. The reactive liquid diluent may serve as one or more of a dispersing medium for the solid pigment particles, a carrier, a coalescent and a humectant, and may crosslink or otherwise cure to form an interpenetrating polymer network in, or crosslink with, a pigmented coating composition containing a film-forming polymeric binder. Embodiments of the reactive liquid diluent can provide colorants and coating compositions having reduced levels of VOCs, conventional carriers, conventional dispersants, conventional coalescents and conventional humectants.