Identifying different elements to customise?

Hi folks,

I’ve been religiously going through all the elements in Customise so that I can add my colour palette and fonts etc, and there’s one section I can’t seem to find! It’s currently white, and is the background of the main content text on every page.

Can anyone help me identify which setting to configure for this? I feel like I’ve been through them all….!

http://www.dukeswinebar.co.uk

https://ww.wp.xz.cn/plugins/styles/