Color configuration in widgetbox.

How can I change a template for building color and font configurability into my HTML/JS widget? The tutorial I'm taken to when I click help says there is a place to configure this so users can alter the color of the widget before they embed it on their site. But I can't find where to make these changes. Right now the one I made has a transparent back. I don't know how to add a color background. The widget in questions is called "ASL Fingerspelling Practice" at widgetbox.

Another small issue is that there's suppose to be an image when it first opens in the browser window but the image doesn't show up. I know that's another issue but I just thought I'd include it here.

I'd appreciate any help. Thanks.