Really cool plugin!
The ServerUtils dependency doesn't work on newest version on 1.21.3, but downgrading ServerUtils to 1.0.8 worked perfectly.
The only problems with the plugin are not being able to use multiple gradients, like in the ChatColor plugin (it works on something else, but is a good comparison) and being forced to use an external database.
Other than that, this plugin is perfect!

An overall good plugin, but some things are broken. Rainbows with saturation don't work correctly and the placeholder isn't being registered. Other than that though, it works great

This works perfectly well. It's the only plugin I could find that actually works