Spectrum colorpicker get color with transparency

A hex string doesn't support transparency. Use color.toRgbString() instead: http://jsfiddle.net/UkmXM/2/

$('#backgroundColorPicker').spectrum({
    color: '#000',
    showAlpha: true,
    move: function(color){
        $('#result').css('background-color',color.toRgbString());
    }
});