* @param transparency A transparency of shadow.
* @return
*/
public Text outline(Color color, double transparency) {
color = new Color(0, 0, color.lightness < 50 ? 100 : 0, transparency);
Shadow shadow1 = new Shadow().offset(1, 0, px).color(color);
Shadow shadow2 = new Shadow().offset(0, 1, px).color(color);
Shadow shadow3 = new Shadow().offset(-1, 0, px).color(color);
Shadow shadow4 = new Shadow().offset(0, -1, px).color(color);
return shadow(shadow1, shadow2, shadow3, shadow4);
}