Is it possible to get this skin tone using just the RGB Curves, white balance, and HSL colors.  I'm trying to do this in Capture One and it almost seems possible with the right combinations but I just can't get it.  It almost seems the red and blues, and maybe magenta, may play into it more.

https://www.facebook.com/billwitz/photo … mp;theater

Can. You are doing the right thing.

Two of the keys are to use Curve adjustment layers.  The biggest factor is to pull down on the center of an RGB curve so that the underlying luminance of the skin gets very dark.  Control/Command I (Invert) your white mask on this layer to black ... then paint on the darkness with a 4% opacity white soft brush (to avoid brush marks) on all the skin.  This will give you the darkness component you need to the look.  The exact brown color is next.

The second key is to use  another adjustment layer to create the orange skin color (or you can do it in the same layer as above if you like.  I like to separate them so I have maximum the visual/artistic control).  To get the brown skin you primarily pull down on the green channel (the skin becomes magenta) and you can also pull down on the blue channel till you get the orange color that you prefer.  You can also pull up on the red channel a bit if you want a warmer orange or more overall color saturation. 
You can sometimes use the same layer mask on this coloring layer that you used on the above darkening layer (to save some time) ...  by alt/option clicking on the mask itself and dragging it up to your new colorizing layer...  and saying YES to the prompt. (Keeps you from having to paint in a new mask.  If it doesnt look Just Right...make a new mask and do a separate color painting mask)

Your original image will play a big role in HOW much of the above to do...the luminance/brightness of the original skin is the key factor.  You might sometimes have to do a Control/Command J to Duplicate the darkening layer again... because your base image is Way TOO bright to begin with.

You are the artist...so keep on experimenting with the darkness component... and the orange component together... till you get the image the way you like it.

Cheers - Good Luck