How to change the background color of a section?

Configuration Frontend
1

Using the new sections in HA, I like to color the background of each section. sections are not visible (at least not in dark mode). Does anyone know how and where to set a style or theme that changes the background color of the section itself? Here is a screenshot of such card:

afbeelding
afbeelding541×507 29.8 KB

Now when I fiddle with web-developer tools in my browser, I could change this:
afbeelding

and that results in the desired result like this:

afbeelding
afbeelding577×516 29.3 KB

How can I set this style using themes or card mod in order to make it permanent?

2

I was also trying to do something similar, but I’d like to avoid using non-standard components (like card mod).
Maybe you can make this a feature request in home assistant?

After all, it should not be too difficult to implement.