I recently tried to change the cursor theme in i3 using lxappearance.
I downloaded a theme from www.gnome-look.org. Then, I extracted it according to the instructions for manual installation here:
~/.config/gtk-3.0/settings.ini got edited.
The result is that in several apps like firefox the new cursor theme is applied. On i3bar, an old cursor theme is used, the same at login via lightdm.
Any idea how the cursor theme can be applied consistently system-wide?