A point-of-sale custom color system for tinting base paints and stains includes an array of powdered colorants, including at least white, green, blue and red colorants, which can be used to tint water-borne paints and stains. When tinting solvent-borne base paints or stains, a synergist containing one or more cosolvents, dispersing agents or surfactants is added to or is a part of the solvent-borne base paint or stains, and enables effective tinting using the powdered colorants.