From my own research it appears this is not possible - but I wanted to ask this forum before I accept that I can't adjust a charts border using app script.
I have no example script to give. The chart is pre-existing, and is not generated by my script. I simply want to set the charts border to white.
Thank you all.
You can achieve this through the UI going to Edit Chart-> Customize-> Chart border color, however, it seems that this cannot be achieved in Apps Script at it seems there might be a bug regarding this behaviour that I took the liberty to report. You can take a look at it here.