[Solved]-fillColor stacking in area chart-Highcharts

if you need to stack, you should have the common x values like in the example

http://jsfiddle.net/dxhdt/

so in your case it can be something like:

 var series = [{
    data: [[85, 0], [155, 220],[265, 220]],
    linecolor: "#e8d0d0",
    fillcolor: "#e8d0d0",
    showlegend: false
}, {
    data: [[115, 0], [215, 220],[265, 220]],
    linecolor: "#d1a1a1",
    showlegend: false,
    fillcolor: "#d1a1a1"
}, {
    data: [[145, 0], [265, 220]],
    showlegend: false,
    linecolor: "#bb8977",
    fillcolor: "#bb8977"
}];

http://jsfiddle.net/43xew/3/