Gradient Fill on Shaded Chart

It would be nice to be able to adjust the gradient fill on the shaded charts. More specifically a darker fill at the top and gradually become lighter as you get closer to the bottom.

I would like to see the ability to add a gradient background as well. I searched the help guides and the only source of a custom programmed version still doesn’t appear to allow you to set the background just the plot itself but I could be mistaken https://help.optuma.com/kb/faq.php?id=250

Something like the example below would be very helpful to illustrate certain indicators.

Gradient Example