Comment 2 for bug 507238

  There is a very simple way to make Plymouth display any logo you want. Open /lib/plymouth as root, and you will see an image file called ubuntu-logo.png . You can replace this file with another png image and rename it ubuntu-logo.png , run sudo update-initramfs -u , and plymouth will then display your new logo. Save a copy of it somewhere, though, as this will have to be redone every time plymouth is updated.

I have tested this in a number of themes, and it will work in any theme that normally displays the ubuntu logo. If you want the kubuntu logo, open it in gimp, resize it to whatever size you want, save it as a png with a transparent background somewhere, and copy it into /lib/plymouth as your new ubuntu-logo.png .