How to change the Dock background

Click on the menu button of your Android phone and then click "Preferences"
Now you're in the menu from the "Go launcher Ex" . Go to "Visual Settings". In the "Visual Settings" menu click on "Dock Background". Here you can choose from several points. We take "Go Theme background"

Now you can scroll left and right by the dock backgrounds. When you find a matching "Dock background". Click on "Set Dock Background"