The chroma of a specific color can be emphasized with respect to an object without affecting the color of illumination light. An illumination light generator generates illumination light to be radiated to the object by adding or subtracting, to or from a reference illumination light spectrum that is an illumination spectrum serving as a reference, an element spectrum in accordance with designated conditions with respect to chroma adjustment from among a plurality of element spectra that are spectra for being added or subtracted to or from the reference illumination light spectrum and for performing chroma emphasis of a specific color without affecting an illumination light color.