Robyn, I'm getting the impression you're not calibrating the shader. There is a color there, initialized to SKIN, but you have to actually choose the color of the lip or whatever it is you're trying to despecularize.

Load the shader. Open a preview on the color map node.

Using the color eye-dropper capability, click on the color chip in the Normal Color node, then click somewhere on the color map where you don't see specular. If it's the lip, click somewhere on the lip.

This is not something you do in Python. You do it in the material room. You click on what is the correct diffuse-only color as an example from the texture you have loaded. Then the shader will use that color as a reference for the correct ratio of diffuse reflection, sans specular.

It compares other points with that reference Normal Color, and things that look whiter than that, it un-whitens.

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)