Sets the color of the Halo.
The default color of halo is 0xFFFFFF:
// the parameter can be a string like "#FF0000" or a hex number 0xFF0000
controller.setHaloColor("#FF0000");
//controller.setHaloColor(0xFF0000);
controller.setHaloColor("#FF0000");
//controller.setHaloColor(0xFF0000);