To provide an endoscope light source device, an endoscope system, and a method of operating the endoscope light source device which make an observation object observable almost as in the case where continuous spectrum light such as white light emitted by a xenon lamp is used as illumination light.SOLUTION: An endoscope light source device 14 includes: a light source unit 20 that has LEDs 20a-20d each independently emitting light of a different color from each other to emit first multicolor spectrum light 27 having a first multicolor spectrum which has light beams emitted by the LEDs superimposed on one another； and a light source control unit 22 that makes an integrated light amount value S1in a first wavelength band of the first multicolor spectrum light 27 match an integrated light amount value S1in a first wavelength band of continuous spectrum light 26 having at least a portion of a wavelength band of white light emitted by a white light source, and that further makes an integrated light amount value S2in a second wavelength band different from the first wavelength band of the first multicolor spectrum light 27 match an integrated light amount value S2in a second wavelength band of the continuous spectrum light 26.SELECTED DRAWING: Figure 6【課題】キセノンランプが発する白色光等の連続スペクトル光を照明光に用いた場合とほぼ同様に観察対象を観察可能にする内視鏡光源装置、内視鏡システム、及び内視鏡光源装置の作動方法を提供する。【解決手段】内視鏡光源装置１４は、互いに異なる色の光を独立して発光するＬＥＤ２０ａ～２０ｄを有し、これらが発光する光を重ね合わせた第１多色スペクトルを有する第１多色スペクトル光２７を発する光源部２０と、第１多色スペクトル光２７の第１波長帯域の光量積分値Ｓ１Eを、白色光源が発光する白色光の少なくとも一部の波長帯域を有する連続スペクトル光２６の第１波長帯域の光量積分値Ｓ１Xと一致させ、かつ、第１多色スペクトル光２７の第１波長帯域とは異なる第２波長帯域の光量積分値Ｓ２Eを、連続スペクトル光２６の第２波長帯域の光量積分値Ｓ２Xと一致させる光源制御部２２と、を備える。【選択図】図６
