Code in boxes is barely visible

Hi! In my company’s XWiki code and links in info boxes are hardly visible, as you can see in the picture:

How can I fix it? Or should it be fixed upstream, maybe?

I’m on v. 16.10.4

Duplicate of How to get the new (16.7+) box macro style after upgrading

@andrea.pt please don’t post several times the same topic. Thx