# Edit Grub bootmenu
sudo grub-mkconfig
sudo nano /etc/default/grub

# Add os-prober for dual boot+
# Remove "#" in Grub infront of os-prober
sudo os-prober

# Save updated grub config to grub
sudo grub-mkconfig -o /boot/grub/grub.cfg

# Menu colours
[Source: https://www.gnu.org/software/grub/manual/grub/html_node/Theme-file-format.html]
# Change inside /etc/defaults/grub
GRUB_TERMINAL_OUTPUT="gfxterm"
GRUB_COLOR_NORMAL="light-blue/black"
GRUB_COLOR_HIGHLIGHT="light-cyan/blue"
# JPG file has to exist in /boot/grub/
GRUB_BACKGROUND="/boot/grub/AI-Hoshino-Oshi-No-Ko.jpg" 

# Grub themes
- https://k1ng.dev/distro-grub-themes/preview
- https://github.com/vinceliuice/grub2-themes