LightDM Background un-settable

I'm running an Arch Linux setup with Budgie as my primary desktop environment. I was using GDM, but I prefer LightDM due to the simplicity of the Slick greeter. Everything is going well, though I can't change the background image from a solid colour at all. I've managed to change it from a solid black to a navy blue (and I assume any hex codes will work at this point), but anything I try to change the LightDM background ends in failure. Help is much appreciated! :)