I'm looking to make a particular plot, and I'm wondering if Nevron Chart provides an easy way to do it.

The plot I want to make for our biologists is a 'leverage plot with confidence bands', which should look something like this: it's basically a 2-d line plot, with a straight line going across the screen with a set slope, and then with curves on either side of the center line, with each curve bending away from the straight line on both ends (for a rough example, see the graphic at this website: http://mtsu32.mtsu.edu:11308/regression/level2/cbands/concept.htm). The core idea is that I want to create a figure that looks like the sideways projection of an 'hour glass', but the hour glass at a tilt and with a line running down the center (through the 'hole' in the hour glass where the sand would flow).

So far so good. Up until now I've been making these plots without color and the users have been basically satisfied. Now, however, they're wondering if I could add color: they want me to take the area between the two curved lines and make it, say, light blue. I'm having trouble, however, figuring our how to do this with the Nevron library. The NAreaSeries invariably pays attention to the y-values or the curves, while my leverage plots might end up in any part of the XY plane: maybe the whole plot will be above y=0, or maybe below it, or maybe crossing it at some location. Also, I don't want any colors above or below the confident bands -- only between them. Therefore I'm thinking that the NAreaSeries, stacked or unstacked, isn't the answer.

But what other chart type could I used to get the effect I'm seeking? And if there is a chart type that can give me what I want, would it then also handle one additional extension, namely 'prediction bands'? This plot would be very similar to the one I've already described, but would add an additional colored area -- picture this time the projection of a fat hour-glass in orange, and then superimpose a skinnier hour-glass with a different color on top of the fat hour-glass, and then place our center line running through the center of the skinnier hour glass? Is any of this possible? Through the years I've made many a plot with the Nevron package that our biologists have called quite beautiful -- surely there's a way to make this new plot too(?)

Thanks for any ideas,
Ben