For all the time (I've known frl mods since last year, but I only signed up in February of this year) I have not found any graphic mods (I do not take into account the retextures of the maps, I am looking for a complete graphic mod or shaders)
There's no such drastically change in frl when comes into graphics mod. Most of them just retexture. But if you mentioned about night mode, I've heard it was for sell