1. Click on Preferences.
2. Click on Visual Styles on the left.
3. Click on Add.
4. Enter a name for the Visual Style.
5. Select type Backgrounds on the bottom left.
You can have several types of backgrounds assigned to a Visual Style.
None
Displays a black background.
Color
Displays a specific colored background.
Image
Displays an image in the background. This image can be tiled or stretched.
Video
Displays a video file in the background.
If you are having trouble with this option, try selected "Use background video safe mode" in Preferences.
Gradient
Fades from one color to another in the background.
Video Capture Device
Displays live video from a video capture source as the background.