bootstrap colorpicker
===

I'm using bootstrap colorpicker (http://www.eyecon.ro/bootstrap-colorpicker/) in my rails project and wanted to get the alpha in my javascript function. Does anyone know how to do this? I can easily get the color from the picker as illustrated in the example as:

     $(function(){
		
			var bodyStyle = document.getElementById('body').style;
		
			$('#cp4').colorpicker().on('changeColor', function(ev){
				bodyStyle.backgroundColor = ev.color.toHex();
				
			});
		});