code: public void setLightDiffuse(int i, Color color) {
  	    float[] tmpColor = {
              (float)color.getRed(),
              (float)color.getGreen(),
              (float)color.getBlue(),
              (float)color.getAlpha()
          };
  		gl.glLightfv(GL2.GL_LIGHT0 + i, GL2.GL_DIFFUSE, tmpColor, 0);
  	}
docs: Sets the diffuse color for No.i light.