FB Refresh allows you to set a custom image URL as your FB homepage wallpaper. This allows endless possibilities of customization.You will never have to see the same login page again :) FB Refresh does not affect any other part of your Facebook, and NEVER has access to your personal data, passwords or anything of the like.
You can enter a custom image URL as the background. This means you can add an image of any dimension, including HD wallpaper. Remember, however, that the larger the image, the slower the load time.
To change the background image to one of your own:
#1 - Install FB Refresh
#2 - Go to your extensions page chrome://extensions/
#3 - Find the "FB Refresh" extension and click the "Options" link.
#4 - Enter your image URL in the box and select if you want it to repeat horizontally or vertically (or both) and click save.
#5 - Visit Facebook.com (while you are logged out) and enjoy!
After Installing extension You can change your facebook Login page with custom wallpapers