Abstract: The real-time infrared and visible color fusion is realized by employing color transfer theory in l space. The structure and workflow of an infrared and LLL color fusion system were designed. Two applications of color fusion in military application were described, including detection of sniper in nighttime and detection of camouflage vehicles. The experimental images were shown. A subjective evaluation of target detectability in image was designed to assess target detectability of experimental images. Experimental results show that color fusion technology could increase military target detectability significantly.