A method is provided of reproducing continuous tone pixel colors of a color image having many pixels based on Kueppers' device states, wherein the Kueppers' device states of a printing device are the printed pixel colors that are allowed based on Kueppers' color separation and halftoning. The method includes selecting a Kueppers' device state in the proximity of a continuous tone pixel color to be reproduced from the printing device's set of Kueppers' device states, and printing the Kueppers' device state. An error is diffused between the continuous pixel color and the selected Kueppers' device state to one or more pixels in the neighborhood.