Fill bottom line area chart by different colors

Hi i have line chart , and x-Asis is time value 12:00-22:00

i change line color by this code

color:function(obj){
var t = obj.time;
var minutes = parseInt(t.split(“:”)[1],10);
if (minutes > 20) {return “orange”};
if (minutes > 40) {return “red”}
return “green”;
}

line chart change color good, but i need fill area under the line on the same color as line …
i try use area chart but it’s fill only one color …

I think the above scenario is not possible with current version of the chart.
You can’t color areas in line chart and area chart can have only one color.