Change chart background color

[imalil]

I'm looking for a way to change my chart bg color based on my conditions being met. For example, my chart bg is always black, but the first bar that makes my condition true I want the bg color to change behind these bars and stay changed until my condition stops being true. So the bg color will only change behind the bars that make the condition true. It will be black all other times.

Is there a function that can do this?
Thanks in advance.

[bltdavid]

Set the BackBrush.