This application allows you to edit the boot screen of modern macs.
Download the latest release: here
Unzip the download
Open the Dark Boot app
Select the color you would like your boot screen to be and press Apply
Enter your admin password and press OK
Reboot
Boot Color
Boot Image
Login Screen Image
Lock Screen Image and Text
Verbose Boot
Safe Mode Boot
Single User Mode
Boot Sound (2015 or older)
Clamshell Mode (Laptops)
Auto Boot (Laptops)
Pretty much the BSD license, just don't repackage it and call it your own please! Also if you do make some changes, feel free to make a pull request and help make things more awesome!