A method for modifying color hue of colored synthetic yarns and/or filaments to a target color hue during a conventional melt-spinning process, characterized in that the method comprises the following steps: - storing color coordinates a t * and/or bt* of the target color-hue including limits of tolerances; - taking measurements of color coordinates a* and/or b* in the colored synthetic yarns and/or filaments to identify the actual color hue; - comparing stored target color hue coordinates with the actual color hue coordinates measured, that is Δa and/or Δb, to determine if the differences, if any, are beyond limits of the target color hue tolerances; - preparing at least one correcting liquid-masterbatch composition comprising a liquid polymer carrier and at least one colorant dispersed therein, with the proviso that one of the colorants included in the correcting liquid-masterbatch composition is selected to be the same as present in the colored synthetic yarns and/or filaments, wherein the colorant concentration is between 1% and 40% by weight to the weight of the correcting liquid-masterbatch composition; - converting the observed differences in the color coordinates, i.e. Δa and/or Δb, into a dose of the prepared correcting-liquid-masterbatch composition; - adding such dose of the correcting-liquid-masterbatch composition during the extrusion of the colored synthetic yarns and/or filaments to correct the actual color hue toward the target color hue, thus resulting in a corrected color hue modifying the actual color hue to be within the target color hue tolerances, wherein the dose is equal to or lower than 3% by weight with respect to the weight of the colored synthetic yarns and/or filaments; and optionally - verifying the corrected color hue in the corrected and colored synthetic fibers and/or filaments by taking new measurements of color coordinates a m * and/or b m * in the newly obtained colored synthetic yarns and/or filaments in order to assure that the corrected color hue is within limits of target color hue tolerances. - storing color coordinates a t * and/or bt* of the target color-hue including limits of tolerances; - taking measurements of color coordinates a* and/or b* in the colored synthetic yarns and/or filaments to identify the actual color hue; - comparing stored target color hue coordinates with the actual color hue coordinates measured, that is Δa and/or Δb, to determine if the differences, if any, are beyond limits of the target color hue tolerances; - preparing at least one correcting liquid-masterbatch composition comprising a liquid polymer carrier and at least one colorant dispersed therein, with the proviso that one of the colorants included in the correcting liquid-masterbatch composition is selected to be the same as present in the colored synthetic yarns and/or filaments, wherein the colorant concentration is between 1% and 40% by weight to the weight of the correcting liquid-masterbatch composition; - converting the observed differences in the color coordinates, i.e. Δa and/or Δb, into a dose of the prepared correcting-liquid-masterbatch composition; - adding such dose of the correcting-liquid-masterbatch composition during the extrusion of the colored synthetic yarns and/or filaments to correct the actual color hue toward the target color hue, thus resulting in a corrected color hue modifying the actual color hue to be within the target color hue tolerances, wherein the dose is equal to or lower than 3% by weight with respect to the weight of the colored synthetic yarns and/or filaments; and optionally - verifying the corrected color hue in the corrected and colored synthetic fibers and/or filaments by taking new measurements of color coordinates a m * and/or b m * in the newly obtained colored synthetic yarns and/or filaments in order to assure that the corrected color hue is within limits of target color hue tolerances.