Widgets and Shortcode styling

Hello, i have the sidebar on a page and a shortcode in the content area. I am using a background on the whole page. I am trying to get it so the container that holds the shortcode has background-color: RGBA(15, 14, 14, 0.63);. as well as the widgets, and the featured properties shortcode. How can i change the background color of all shortcodes and widgets?

you can see my page at http://www.irealvest.com/
http://www.irealvest.com/homes-for-sale-featured/

https://ww.wp.xz.cn/plugins/optima-express/