code: public void setColor(float red, float green, float blue, float opacity) {
  		setColor(red, green, blue);
  		setOpacity(opacity);
  	}
docs: Set the color with arithmetic RGB values
  
  @param red
  red float color inclusively between 0.0 and 1.0
  @param green
  green float color inclusively between 0.0 and 1.0
  @param blue
  blue float color inclusively between 0.0 and 1.0
  @param opacity
  opacity float inclusively between 0.0 and 1.0