Abstract: A solid colorant dispensing unit for dispensing charges of solid spherical colorant particles in a time-controlled way, the dispensing unit having a supply container having a nozzle for dispensing the particles having a number average particle size and a number particle size distribution, wherein a ratio of the standard deviation of the number particle size distribution to the number average particle size of the particles is less than 25%. The nozzle having a dispensing outlet having a diameter taking into account the number average particle size of the particles. The dispensing unit having a control assembly for controlling the dispensing of the charges of the particles by taking into account the properties of the particles and the diameter of the outlet of the nozzle. A tinting machine having the solid colorant dispensing unit.

Abstract: A solid colorant including a. 30-97 wt % of a pigment, b. less than 5 wt % of a solvent c. 3-40 wt % surfactants and wherein: the ratio S/A [Std dev of the particle size distribution/average particle size] of the solid colorant is <25%, preferably <22% and more preferably <20%, wherein wt % is relative to the total weight of the solid colorant, and wherein the particle size distribution is determined with light scattering with fully automated image analysis according to ISO 13322-1 Static image analysis First edition 2004 Dec. 1 by the use of the OCCHIO ZEPHYR ESR analyzer. A process for making the solid colorant, and the use of the solid colorant for tinting base paints by volumetric dosing of the solid colorant to the base paint.