One embodiment of the invention provides a system that automatically resolves conflicts between phase shifters during creation of a phase shifting mask to be used in an optical lithography process for manufacturing an integrated circuit. Upon receiving a specification of a layout on the integrated circuit, the system identifies critical-dimension features within the layout. Next, the system places phase shifters comprised of phase shifting geometries on the phase shifting mask to precisely define the critical-dimension features. In doing so, the system identifies junctions within and/or between the critical-dimension features, and removes phase shifting geometries associated with the junctions to obviate coloring conflicts between phase shifters on the phase shifting mask. In one embodiment of the invention, the junctions include T-junctions and/or L-junctions.