anychart.onDocumentReady(function () {
var stage = anychart.graphics.create('container', 600, 400);
var chart = anychart.gauges.linear([15, 20, 25, 30, 44]);
var tankPointer = chart.tank(2);
var state = tankPointer.normal();
state.emptyFill('#FF9800', 0.4);
chart.title('Set state fill with opacity for the empty part of a tank with opacity');