1. a method for avoiding objectionable moiré in a color image, the: method comprising: identifying a problematic excitation angle associated with a problematic excitation in a marking process or in the color image; selecting a set of at least two halftone screens for rendering at least two separations of the color image wherein the set of screens is selected to avoid including significant screen fundamental, harmonic and beat frequencies at angles closer than about 1 degree of the identified problematic excitation angle; and halftoning the color image according to the selected set of screens.