[FEATURE] Fill Color of Overlap Area

I’m using ChartJS V2 to create a chart. Chartjs V2 supports the fill color feature. But I would like to fill overlap area with different color. Please see screenshot below. I have two line. A represents overlap area for two lines.

Example :

I would like to fill with 3 different color for 2 lines. When the Line1 and Line2 overlaps, fill color should be A If Line1 does not overlap Line2, fill color should be B If Line2 does not overlap Line1, fill color should be C

I created a fiddle for this. See Fiddle http://jsfiddle.net/qcs1t9ag/