https://www.ericsbinaryworld.com/2006/01/17/changing-your-grub-screen/
While I was fiddling with grub as part of my experiment to get rid of the graphical boot, I noticed the picture grub uses when I boot in. For Fedora Core 4 users, I’m talking about the blue screen with the words Fedora Core where grub gives you a few seconds to choose a different kernel or OS before booting in. I decided to make my own, to truly customize my computer! Afterall, that’s one of the things that REALLY attracts me to open source.