1. An image display apparatus comprising: a display unit that displays a series of images obtained by imaging an inside of a subject in time sequence, and displays a time bar indicating imaging periods of the series of images so that areas of the time bar are identified by different colors corresponding respectively to regions of the inside of the subject; and a control unit that identifies the respective regions of the inside of the subject, which are displayed on the series of images, and controls the display unit so that, for each of the regions identified, an area of the time bar corresponding to a period when a series of images of the region are displayed is colored with a substitute color identifying the region, wherein the control unit detects color information of each of the series of images to identify the respective regions of the inside of the subject based on the color information, the substitute color coloring the area is determined independently of the detected color information, and the substitute color has contrast to form a border with an adjacent substitute color on the time bar.