Grub 2 - little customisation and one question

[PokerLegion]

First, I want to remove this white square if this is possible (this around boot entries) and second, even if i choose wallpaper in resolution of my monitor (1366x768) wallpaper is not set full screen but is centered as you can see on my screenshot (sorry for bad quality) but why? Thx in advance

[JRV]

Have you tried grub customizer?

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer

[PokerLegion]

I use kubuntu so i installed this: http://kde-apps.org/content/show.php?content=139643 but i will try grub customizer, thanks.