If you change the gain & refresh the preview, you will see the B&W hair mask change. You want it to basically be blown out white, with only any hair showing dark, (eyebrows, or hair on the head if the texture has it). Sometimes if you check the hair mask box on the other materials (body, neck, etc.) it will show the redness you're having, from miscalculation of the SSS.

Poser Pro 2012 SR3 on Win10 x64 w/Reality.
Poser Display Units = inches.