How to change the background color of a report?

[jtsetsos]

I just tried to change background color of a report that displays a chart using the method described as above and it doesn't work, well it fails to load the settings when I restart splunk with the following errors, note I have also tried with quotes and without and also in ["0xffffff"] and ["#ffffff"] and [#ffffff], none of the options work:

    Checking conf files for problems...
            Invalid key in stanza [PieChartByCountry_Report] in /opt/splunk/etc/apps/search/local/savedsearches.conf, line 31: display.visualizations.charting.backgroundColor  (value:  "#000000").
            Invalid key in stanza [PieChartByCountry_Report] in /opt/splunk/etc/apps/search/local/savedsearches.conf, line 32: display.visualizations.charting.fontColor  (value:  "#ffffff").
            Invalid key in stanza [PieChartByCountry_Report] in /opt/splunk/etc/apps/search/local/savedsearches.conf, line 33: display.visualizations.charting.foregroundColor  (value:  "#ffffff").

I checked the documentation found at:

https://docs.splunk.com/Documentation/Splunk/7.2.6/Admin/Savedsearchesconf#Display_Formatting_Option...

And there is no mention of these specific settings anywhere in this document, not even in the deprecated section of the document.

errr uhmmmm so what gives here?

Is it possible to change the background/foreground colors of an embedded report that displays a chart or not?

I'd like a black background with white text foreground, is this at all possible?

Kind Regards
Jim