The desktop background is the image or background color that is applied to your desktop.
To access the Desktop Background Preferences:
Right-click on the desktop, then click Change Desktop Background.
Click Desktop > Preferences > Desktop Background.
You can customize the desktop background in the following ways:
Select an image for the desktop background. The desktop background color is visible if you select a transparent image or if the image does not cover the entire desktop.
Select a color for the desktop background. You can select a solid color or create a gradient effect with two colors. A gradient effect is a visual effect where one color blends gradually into another color.
Chapter 2 Preference Settings