I've recently found time and need to improve my GRUB 2 setup and I hope sharing that could help somebody, although it is not something you won't find in other HOWTOs.
I'm quite conservative and not spending in boot screen much time so all I use is text mode.
First of all, the location of onfig files. All the configuration settings are in /etc/default/grub. The settings are used as variables when you generate a new GRUB configuration. The settings there are used whe you generate a new GRUB configuration /boot/grub/grub.cfg with grub-mkconfig command and are all you usually need to change.
hwinfo | grep -i framebuffer
menu timeoutSetting menu-style timeout, with 5sec countdown:
The palette for text-mode colors is quite limited, valid color names are: black, blue, brown, cyan, dark-gray, green, light-cyan, light-blue, light-green, light-gray, light-magenta, light-red, magenta, red, white, yellow.
There are two config options, for setting normal and highlight colors, in format foreground/background: GRUB_COLOR_NORMAL=white/blue GRUB_COLOR_HIGHLIGHT=yellow/light-blue
As it seems these settings are ignored, I created file /etc/grub.d/99_set_colors with following content to fix that. It's rather simplistic as it does now allow any spaced or quotes around the color values but it does the job:
recalling previously selected menu entry
GRUB can save the menu entry you selected last time and use it as default for the next boot:
Example with the greeting from the film Close Encounters of The Third Kind: GRUB_INIT_TUNE="480 900 2 1000 2 800 2 400 2 600 3"
You canl find other well-known tunes on internet, e.g. in Linuxmint forum .