How can I change the background color of a contact box? [closed]

The way to determine what to change is to use browser development tools, like Firebug on Firefox. With those tools, you can determine the CSS that is being used in a specific part of the page.

Once you determine the CSS class to change, you can put that CSS in the Custom CSS area of your theme (in the Customizer, if supported). Something like, if the contact box has a class called contactbox, then you would use CSS similar to

.contactbox {background-color:#888888; }

If an ‘id’ is used, then your Custom CSS would be similar to:

 #contactbox {background-color:#888888; }

If your theme does not support Custom CSS, then you will need to create a Child Theme and put the above CSS in the Child Theme’s style.css file.

You don’t want to modify the theme’s CSS, as any changes you make will get overwritten on a theme update.