Board Thread:Support Requests - Getting Technical/@comment-28941090-20191012132827

Hello. I am the sysop of Greek Pro Wrestling wiki and would like to change the background color of the wiki's infoboxes. I've edited the MediaWiki:Common.css and even got to the point where I copied the MediaWiki:Common.css page of Pro Wrestling Wiki (the English one). I am wondering if some Templates or any other pages are needed for it to work properly.

For example, this is a pagethat needs to be changed and I would like it's infobox background color to look like the one here. Can you please help? 