A while ago I installed kubuntu-desktop to try out Plasma, didn't like it, and deleted it. I notice though that when I start the computer up the splash screen still says "Kubuntu". When I'm on the login screen for more than about ten seconds, the screen goes completely blank. This isn't much of a problem because I can still type my password and login and the display returns to normal when I do, but it's an annoyance.
Edit: Also I tried
sudo update-alternatives --config default.plymouth
and I selected the ubuntu-logo.plymouth, but it had no effect.
sudo update-initramfs -u
to take effect.