Hi,
I have a quick question about the Explorer option that is available for charts with a continuous axis. This feature is working great for my needs, but I'd really like the option to customize the color of the highlighting box that is created when users drag-to-select a region. At the moment the default fill is a semi-transparent blue color (see image below) but after a fair bit of effort I still can't figure out a way to reliably customize this to make the charts fit more naturally with the color scheme of my site.

I appreciate that the Explorer feature is marked as "experimental" but I was wondering if there are there any reliable workarounds to achieve this on the current Google Charts build? Alternatively, do you guys have any plans to implement an option to customize this property in future builds (e.g. an explorer.color setting that accepts an rgba value)?
Many thanks and keep up the great work, Adam