I have written a tutorial about how to install and change Ubuntu Plymouth (initial splash screen),and that’s in command line.Here’s a GUI called Splashscreen Manager,for managing your GNOME splash screen images. It provdides a nice image list with options to add, remove images and set one of them as an active splash screen image.

Splashscreen Manager depends on:

ibgconf2-ruby (>= 0.11.0)
GConf 2 bindings for the Ruby language
dep: libglade2-ruby (>= 0.11.0)
Libglade 2 bindings for the Ruby language
dep: ruby (<< 1.9)
An interpreter of object-oriented scripting language Ruby
dep: ruby (>= 1.8)

Download SplashScreen Manager the deb from:http://gnome-look.org/content/show.php/Splash+Screen+Manager?content=134231.

After install the deb,run the application from System -> Administration -> Splash Screen Manager,and you will see:

To install a theme,you need first download plymouth themes (with .tar.gz extension) from gnome-look.org -> Splash Screens,and then click the “Install” button to select the downloaded theme.There are a few themes come with Ubuntu in the default repository,you can find them with this command in Applications -> Accessories -> Terminal:

apt-cache search plymouth-theme

and install them with:

sudo apt-get install plymouth-theme-*

Finally,after you changed the plymouth theme you can check the effect with this command without restart the machine:

sudo plymouthd
plymouth --show-splash

quit the preview with:

sudo plymouth quit