Colored Region only Rectangluar shape ?

[CognosBIUser1]

Quick question guys!.

I want to colored the regions within the graphs based on tolerance that changes every month.
I want the colored region to go up and down along the x axis depending on the monthly tolerance values.

I have actuals on the Y - axis and Months along the X- axis.
The tolerance changes month to month so the Green , yellow and Red region changes depending on the month.
Can I high light the graph region based on this ?
What I am seeing now is that its a rectangular colored region only.

This is in cognos 10.2.2. Report studio.
Chart type Combinational.

Does this have to do with the Start / End Category Position ?

[CognosBIUser1]

It looks like we can only do rectangular colored region. Found an alternative by doing area graphs and now i am able to achieve the colored region in non rectangular shapes.