1. An image capturing apparatus for generating, from a captured image created by capturing an image of a subject in accordance with an image capturing condition specified by a user, image data represented in a predetermined color space selected from among a plurality of color spaces, comprising: a detector which detects, from the image data, an out-of-gamut region falling outside the color gamut of the predetermined color space in accordance with the image capturing condition; and an out-of-gamut-region display unit which displays the out-of-gamut region.