Grub2 is the new bootloader found on many recent Linux distributions. It is more difficult to configure than the old Grub where you can just edit /boot/grub/menu.lst. In Grub2 a couple of scripts are executed in order to create a configuration.

The file /etc/default/grub contains general settings for the menu. By default no menu is shown if only 1 operating system is installed, even if this operating system has more than 1 kernel to choose from. To display a menu anyway, comment out GRUB_HIDDEN_TIMEOUT (insert a # at the beginning of the line).

The file /etc/grub.d/05_debian_theme configures the appearance of the menu. To change the colors, for example, change the lines:

set menu_color_normal=white/black
set menu_color_highlight=black/light-gray


set menu_color_normal=white/blue
set menu_color_highlight=blue/white

This gives a white text color with blue background. The selected item will have a blue text color with white background.

Also checkout the other files in /etc/grub.d. After editing, run: