I installed a Grub theme Archxion the way described here : https://github.com/Generator/Grub2-themes#faq
But only screen resolution was changed. Nothing more. Default black screen without background.
Also I tried to install theme from AUR package with the same result.
grub-mkconfig was launched on every installation.
May be I missed something?
Fixed. Just fogot to uncomment theme path line in /etc/default/grub