LED based illumination modules are realized that are visually color matched to light sources not based on LEDs based on visually matched color spaces. A visually matched color space is employed to both instrumentally and visually match an LED based light source with a light source not based on LEDs. In one aspect, an LED based illumination module is realized to achieve a target color point in a visually matched color space within a predetermined tolerance. In another aspect, an LED based illumination module is realized to visually match a light source not based on LEDs. A target color point in the CIE 1931 XYZ color space is derived based at least in part on the spectrum of the visually matched LED based illumination module. LED based illumination modules visually matched to light sources not based on LEDs are realized based on the derived target color point.