This is my splashy background.

Howto (Mandriva 2009.0):

FOR MONITOR 4/3 - RESOLUTION 1024x768

# su
password: your root password

# cp -i /home/YOUR-HOME/Immagini/Sfondo.jpg /usr/share/splashy/themes/Mandriva-Free-1024x768/background.jpg

#eval `dbus-launch --auto-syntax` kwrite /boot/grub/menu.lst

Change VGA=788 to VGA=791 (1024x768@16b) or VGA=792 (1024x768@24b)
SAVE

Edit this file /usr/share/splashy/themes/Mandriva-Free-1024x768/theme.xml whith this number

Progressbar dimension
x 25
y 73
with 50
height 2

Progressbar color
Red 0
Green 150
Blue 255
Alpha 214

Progressbar border color
Red 0
Green 114
Blue 193
Alpha 255

Progressbar background color
Red 255
Green 255
Blue 255
Alpha 150

Save

#bootloader-config --action update-splash