The invention provides an adjusting method of light color, a device, a light modulation driving circuit and a lighting system. The method comprises steps of determining a reference bright color parameter of a to-be-adjusted light source based on a reference output current value of the to-be-adjusted light source; determining a target bright color parameter of the to-be-adjusted light source; according to the reference output current value, the reference bright color parameter and the target bright color parameter, calculating an actual output current value of the to-be-adjusted light source and determining an actual bright color parameter of the to-be-adjusted light source; and calculating a difference value between the actual bright color parameter and the target bright color parameter, and if the difference value of any specific parameter is larger than a preset difference value, carrying out iteration on the actual output current value of the to-be-adjusted light source until the difference value of each specific parameter between the actual bright color parameter and the target bright color parameter is smaller than the preset difference value. According to the invention, iteration adjustment is carried out on the actual output current value obtained through calculation, so the to-be-adjusted light source will not have an expected color and/or brightness suddenly, so a phenomenon of glittering is effectively avoided.