1. A method of mapping a full color image producible on a highlight color image output device without mixing highlight color and black for any single object, the method comprising: inputting a full color image including at least one object to be printed in black and at least one object to be printed in highlight color on the highlight color image output device, the at least one objects being defined by a plurality of pixels; converting each object of the full color input image into an intermediate color space image that maintains luminance of the full color image; transforming each object from the intermediate color space image to render each object of the full color image as an object containing only pure highlight color or black while maintaining the luminance of the full color image; and printing with the highlight color image output device the at least one object in black and the at least one object in highlight color in an output image on an image forming medium, wherein the transforming renders an object of the at least one object in black only when a majority of the pixels of the object have a luminance close to neutral within a tolerance.