If you choose a background color using the Customizer in the Resurrect theme and the color does not show, make sure there is not a background image already set. If an image is set, it will cover the color.
Go to Appearance > Customize and click on Background Image. Click on the image box then click Remove Image.
If you are wanting to use a colorable background image, click Presets then hover over the thumbnails to find a preset that says Colorable.
Now you can click on Colors and choose your background color.