process for making producer - colored fibers , yarns , films and related products by extruding from a source , such as from an extruder , a flow of polymer to a spinneret placing in the path of flow between the polymer flow and the spinneret a dye solid or pigment solid having a predetermined shaped surface area , and flowing the polymer into contact against the exposed surface of the dye solid or pigment solid and by such contact dissolving at a predetermined rate a predetermined portion of the dye solid or pigment solid into the polymer flow and coloring the polymer flow for subsequent extrusion from the spinneret as colored filaments .