
Hi @Harry N Nomikos ,
Unfortunately, it is not possible to change the border color of the SharePoint list section using JSON formatting. Body sections configuration does not support advance JSON customizations.
Unlike the header and the footer, body configuration only allows defining one or more sections and adding one or more columns into each of those sections.
Reference:Configure custom body with one or more sections
Here's a similar thread, check it out: Add background-color or any css to "Section" in List Form in SharePoint Online using JSON formatting
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.