A method of determining colorability of a layer of a semiconductor device includes iteratively decomposing a conflict graph to remove all nodes having fewer links than a threshold number of links. The method further includes determining whether the decomposed conflict graph is a simplified graph. The method further includes partitioning, using a specific purpose processing device, the decomposed conflict graph if the decomposed conflict graph is not a simplified graph. The method further includes determining whether the decomposed conflict graph is colorable based on a number of masks used to pattern the layer of the semiconductor device if the decomposed conflict graph is a simplified graph. The method further includes flagging violations if the decomposed conflict graph is not colorable.