1. An image data creation apparatus for creating color image data, comprising: an image data acquisition section configured to acquire image data corresponding to a black-and-white image which allows a feature thereof correlated with a color to be represented by a density level of one single color; a color determination section configured to determine a corresponding color which corresponds to the feature included in the black-and-white image; and a color image data creation section configured to create the color image data corresponding to a color image which allows an image area thereof indicating the feature to be represented in the corresponding color.