1. IN A PROCESS FOR COLORING SOLID, FIBROUS AND PULVERULENT SUBSTRATE MATERIALS WITH A COLORING AGENT SELECTED FROM THE GROUP CONSISTING OF ANIONIC DYESTUFFS AND PIGMENT COLORS, THE IMPROVEMENT THAT COMPRISES PROMOTING ENHANCED AFFINITY OF THE SUBSTRATE MATERIAL FOR THE COLORING AGENT BY APPLYING TO THE SUBSTRATE AN AMINOALKYL SILICONE COLORING ASSISTANT SELECTED FROM THE GROUP CONSISTING OF MONOMERIC AMINOALKYLSILANES, AMINOALKYLPOLYSILOXANES, COPOLYMERS OF AMINOALKYLPOLYSILOXANES WITH AT LEAST ONE OTHER POLYSILOXANE FREE OF AMINOORGANO GROUPS, SUCH AMINOALKYL SILICONE COLORING ASSISTANT CONTAINS ONE AMINO SUBSTITUENT FOR EACH AMINOALKYL GROUP THEREIN AND THE NITROGEN ATOM OF THE AMINO IS CONNECTED TO A SILICON ATOM OF THE SILICONE DIRECTLY THROUGH A DIVA LENT HYDROCARBON RADICAL AND THE AMINO NITROGEN ATOM IS SEPARATED BY AT LEAST THREE CARBON ATOMS FROM THE SILICON ATOM.