code: public void setGradationColor(GradationMode3D mode, ColorSet colorSet1, ColorSet colorSet2) {
          setGradationColor(mode, new RGBColor(colorSet1), new RGBColor(colorSet2));
      }
docs: Sets the gradation mode and colors.
  
  @param mode The mode of gradation.
  @param colorSet1 The colorSet for gradation.
  @param colorSet2 The colorSet for gradation.
  
  @see casmi.GradationMode2D