Just curious, what are you are trying to accomplish?  I've never changed the shadow color before myself. 

  It appears that it's doing what it should be doing.  The small recessed cubes on the dark side of the large cube are being shadowed by the large cube, therefore they're being affected by the shadow color accordingly just like the plane that the model is sitting on.  The darker areas are facing away from the light source, so they are not shadowed ... they're just not receiving light from the source.

 

Reddog9
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