A color cover/change/mixture structure of a light bulb/tube/fixture includes an enclosure, a base, a cold cathode fluorescent lamp tube, and a color cover. The enclosure is a tubular body having a non-light-transmitting or light-transmitting top and a light-transmitting bottom. The base has a bottom surface having retention pawls for engaging and retaining the cold cathode fluorescent lamp tube. The cold cathode fluorescent lamp tube, after combined with the base, is disposed and mounted in the enclosure. Heads are mounted to two ends of the enclosure. The color covers have different colors and are selectively mounted to the enclosure to change the color of light emitting from the cold cathode fluorescent lamp tube.