Urko Mint Dark is a theme for Plymouth, the boot splash tool for Linux. It's designed with Linux Mint in mind, but can be used in any installation that uses Plymouth. It is mainly based on Dark Mint by Josep Sayol and it is intended to be used in conjunction with the Grub GFX theme of the same name. The idea is to keep the same design from the boot splash to the desktop.
How to install the theme:
1. Download the archive
2. Extract it in the directory of your choice
3. Open the new created directory (urko-mint-dark)
4. Read the README.md file