A color image processing apparatus and method capable of changing/converting an inadequate-exposure image or an over-exposure image into an apparently natural image or a pleasing-lightness image. The apparatus is equipped with an object color designating section for designating an object color in an input color image, an optimum color setting section for setting an optimum color corresponding the object color, a lightness conversion factor obtaining section for obtaining a lightness conversion factor based on the object color and the optimum color, and a lightness converting section for converting the lightness of the color image using the lightness conversion factor to create a lightness-changed color image. This apparatus is useful in correcting lightness over a color image input from a digital camera, an image scanner or the like.