An image conversion apparatus for image-converting input color image signals, and outputting the converted signals to an output apparatus, allows execution of a plurality of different color processing operations, checks if an input color image falls within a color reproduction region of the output apparatus, and changes the color conversion processing result to be output depending on whether or not the input color image falls within the color reproduction region of the output apparatus. For example, when the input color image falls within the color reproduction region of the output apparatus, color reproduction color-matched with input color image signals is performed. When the input color image falls outside the reproduction region, color reproduction is performed by color conversion processing assuring highest color reproducibility.