Mysticeagle: if you are referring to the application of VSS, the recommendation would be to name your characters differently and address each character in their own VSS Prop rules.  By default, VSS will apply to all models bearing the same material zone names.  And if that is your intention, then 1 prop is enough.

3dBim: The very first thing that came to mind is gamma correction, but I needed to verify which Poser version you're running.  Check on the lower right hand corner of the render settings.  If Gc is set to 2.2, you may be overcompensating with your lighting causing a washout effect.  Either set Gc to 1 or lower your light intensity.  I would think for cartooning purposes, Gc=1 would serve you best. On the other hand, if Gc is already set to 1 and you are experiencing underlit scenes, lights might be the problem.  Are you using purchased light sets, Poser default or home-made?  Are they spots, infinites, or points?  No need to crank the render settings to the highest, it's a waste of computer resources.  Maybe some screencaps of your render settings and lights may shed some more info.