1. An image processing apparatus that displays a captured image such that the captured image is divided into a plurality of areas, the image processing apparatus comprising: a detecting unit that detects a foreground area including a foreground object, a background area, and a boundary area between the foreground area and the background area, from data of the captured image, which is a processing target image; a display control unit that executes control to display the boundary area in a first classification color that is distinguishable from other areas, and the background area in a second classification color that is different from the first classification color, when the processing target image is displayed; and a changing unit that selects, in accordance with an instruction from a user, one pair of colors to be the first classification color and the second classification color, from among a plurality of pairs of colors for the first classification color and the second classification color that are specified beforehand, and changes the first classification color and the second classification color displayed by the display control unit to the selected pair of colors.