Here is a small snippet to change your background-color into a great image.

Just like this: Hover me

margin

 

Just add the following css in the “advanced customization” section of your editor:

.item-input-wrapper {
background-color: #0099C7;
}

Obviously you have to change the url code “#0099C7” for your own.

Information:
That modification changes all of your features’ backgrounds