If you are using PoserPro (any version), Apple_UK, then GC is inbuilt in the programme - it's a tickbox and a number setting.
If not, it's a bit more complex. And I really think this is where people are having issues: GC is NOT a simple solution, despite Bantha's wacro.
I'd be happy to hand hold you to as far as I've been able to go with this... it's a bit time-consuming, but well worth it in the end, from a colour-accuracy standpoint, that is.

VSS is a shader-distribution tool developed by BagginsBill for complex figures. He has included skin shaders in the tool to illustrate its use. A link to the most recent one (along with the tool) can be found in BB's signature tag.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks