tech-tips/Программное обеспечение/ОС и загрузчики/Linux/DE, themes and styles/Set plymouth theme (boot screen).md

$ apt search plymouth-theme
... find theme you need, e.g. kubuntu's one

$ sudo apt install plymouth-theme-kubuntu-logo

$ sudo update-alternatives --config default.plymouth
... choose needed one

https://askubuntu.com/questions/2007/how-do-i-change-the-plymouth-bootscreen