If You arerunning Rocket dock, then the Tie Interceptor folder is ready for use.

For other docks, just replace the background.ini from inside the folder for one the below.

If you are running Object Dock, rename the objectdock_background.ini to background.ini and place the folder in your My documents>stardock>objectdock library>backgrounds folder.

If you are running Y'z Dock, rename the yzdock_bg.ini to bg.ini and place the folder in your yzdock83\backgrounds folder.

Have fun!