An endoscope system includes a light source that irradiates a predetermined first and second narrowband light； an imaging sensor that captures an image of return light of the first narrowband light and the second narrowband light from the subject, and generates an image signal of the image； and a processor being configured to identify a first color of a first portion and a second color of a second portion based on a difference of an optical density with respect to hemoglobin in the image signal in every frame of the image, the first portion corresponding to a bleeding area, and the second portion corresponding to an area other than the bleeding area within the subject, and correct the first color and the second color based on the identified first and second color while maintaining a color difference between the identified first and second color in a predetermined range.
