Oh, and I think I just figured out some GC color math issues.  If you use GC, when you do color adjustments of any kind, it throws them off.   For instance, if you take a 50% grey swatch and plug it into both slots of a color math node, you'll get a color less than white.  The solution is Gamma nodes.  If you want to adjust a color or image before putting it into a shader, you need a Gamma node with nothing checked for each color or image, and a Gamma node with invert checked after the final color adjustment and before shading.  That will make the adjustment work the same with GC on or off.

Latexluv - Not exactly on the Scatter node.  The Scatter node without Use_Material_Color checked seems to scatter white or close to it.  The Scatter node with Use_Material_Color checked seems to scatter the color of the Material preset you choose in the pulldown menu.  None of which is as customizable as Custom_Scatter, which lets you set surface, scatter, and pre-scatter (useful for a 2nd or 3rd layer of scattering) colors. 

For a quick and easy solution if you already use Scatter, try checking Use_Material_Color with different Material presets. 

In terms of specular, that completely depends on the shader you're using.  EZSkin2 gives you the option of controlling specular.   But the most simple solution is lowering the Reflectivity and raising the RollOff.