XF 1.5 Overlay in background picture in notices...

[click here]

Okay, so I was able to reproduce a background picture in a notice like in this video: https://xenforo.com/help/notices/

But don't quite understand how they got the darker overlay under the text like around the 7:20 mark in the video. Do I have to create a new class etc.?

 

[Paul B]

That's just achieved using custom HTML and CSS for the Notice content.