PROBLEM TO BE SOLVED: To provide an endoscope system and an operation method thereof capable of improving a red image in quality and providing a high quality observation image by a color emphasis processing.SOLUTION: A light source device includes a first light source to emit red light LR, a second light source to emit green light LG, and a third light source to emit blue light LB. A light source control controls the light source device to emit the green light LG independently from the red light LR and the blue light LB, and emit the red light LR for longer emission time than the green light LG and the blue light LB. In addition, the light source control increases emission intensities of the red light LR, the green light LG, and the blue light LB in this order. An imager is a complementary color type image sensor that receives return light from an observation object irradiated with the emitted light. An imaging control controls the imager to receive the green light LG independently from the red light LR and the blue light LB.SELECTED DRAWING: Figure 7
