This mod is entirely based on GravityBox. I just took the relevant parts out and packaged it in a new module, as I only needed this particular tweak on my S 4.
Xposed Lockscreen Background simply allows you to change the lockscreen's background. You can set a solid color or a custom image.
- @C3C076 for GravityBox
- rovo89 for the Xposed framework
- Sergey Margaritov for ColorPickerPreference