The default face set color is white, so we can skip drawing the default face set. This allows to enable again the optimization of not drawing overlays in nodes where the mask is empty. This will still slow down the viewport when a new face set is created for the whole mesh or when inverting the mask, like in previous versions. I also renamed the function to make more clear that now it is checking for both mask and face sets. Reviewed By: brecht Maniphest Tasks: T74692 Differential Revision: https://developer.blender.org/D7207