A full-color flexible light source device is disclosed. The device includes a plurality of light source units each comprises a red LED, a green LED, and a blue LED arranged in the shape of a triangle. Each of the R, G, and B LEDs is a bare chip and the R, G, and B LEDs are encapsulated as a C.O.B. type RGB light source unit. The device is able to emit a uniform light. Also, the device has an increased tensile strength and flexibility as well as has waterproof and vibration-proof features. In other embodiments, the device is encapsulated by elongated, flexible, parallelepiped inner and outer fixing members or formed on a strip.