5 Steps for Customizing Desktop Wallpaper in Ubuntu

To change the desktop wallpaper settings within Ubuntu right click on the desktop.

In the menu that appears, click Change desktop background, this will show the Appearance Settings screen.

You can also bring up these setting with the dash -- by either pressing the super/windows key or clicking on the top item on the launcher and typing "appearance" into the search box.

Click on the Appearance icon when it appears.

The Appearance settings screen has two tabs: Look and Behavior.

The to change the desktop wallpaper, click on the Look tab.

The default screen shows the current wallpaper on the left side of the screen and a drop-down on the right side with previews underneath.

By default, you will see all of the images in the wallpapers folder. (/usr/share/backgrounds).

You can choose one of the default wallpapers by clicking on the image you wish you use. The wallpaper will change as you click. 

You can also choose images from the Pictures folder under your home directory.

Click the drop-down item, Wallpapers, and choose the Pictures Folder option.

All the images suitable for use as wallpaper will be displayed as previews in the right pane.

Clicking on an image changes the wallpaper automatically.

By clicking on the + (plus symbol) at the bottom of the screen, you can add a wallpaper to the pictures folder. Clicking the - (minus symbol) removes the selected wallpaper.

If you prefer to use a plain color as your wallpaper or you would like to use a gradient, click on the drop-down again and choose Colours & Gradients.

Three square blocks appear. The first block symbolizes a plain color, the second block symbolizes a vertical gradient and the third block a horizontal gradient.

For a plain colored wallpaper, you can choose the color by clicking on the little black block next to the + (plus symbol).

A palette will appear from which you can use to choose the color you prefer.

If you don't like the colors that appear, click on the + (plus symbol) within the Pick a color screen.​

You can now choose a color from the left side and a shade by clicking in the large square. Alternatively, you can use HTML to pick your desktop wallpaper color.

When you choose either of the gradient options two blocks will appear next to the plus symbol. The first block lets you choose the first color in the gradient and the second the color it fades to. 

You can inverse the gradient by clicking the two arrows between the two colored blocks.