Change Layout default Background Color

The target is to replace the default value of the layout background-color. The user should create a new template and the bg color is white and not black.

I know that there is a workaround with templates, but i would like to set it realy as default.

My plan was to figure out where the template is created. I can see this in /lib/Controler/Layout.php is. And the class is simple called add()

A litte bit later in the document is an explanation:

 *  @SWG\Parameter(
 *      name="backgroundImageId",
 *      in="formData",
 *      description="A media ID to use as the background image for this Layout.",
 *      type="integer",
 *      required=false
 *   ),

But now is my problem, that i’m to bad in programming php. Where can I add the parameter in the add() function to change the default value?

So my question is: Who can help me to add this parameter or is there a third option to realize that?

PS: I now that this “hack” wouldn’t be upgrade save.

The default background colour is not configurable, you would need to modify the code to change it.

I would recommend using the template solution you mentioned in your post, as this will still ensure all layouts have a white background.

Many Thanks.