This by markschum worked, but had to change Specular_Value to Highlight_Color

Now, the problem, I may be changing the spec color for 40+ intances, so,

any way to make the color picker pop up to choose the color?

I have a mat that I apply to the preview that has the colors I need and I choose from there

 

Quote - So you want a different image map for the diffuse and change specular color to a new RGB value ?

Thats not too difficult. I should have one somewhere in my zips .

Here is one offhand that you can copy and paste to set specular color

import poser
scn = poser.Scene()
fig = scn.CurrentFigure()
mats = fig.Materials()
if mats:
    print fig.Name()   
    for mat in mats:
        tree=mat.ShaderTree()
        n = tree.NodeByInternalName("PoserSurface")
        if n:
            i = n.InputByInternalName("Specular_Value")
            if i:
                i.SetColor(0.5,0.5,0.5)  # replace with rgb values
        tree.UpdatePreview()
scn.DrawAll()