So, there is this easter egg where you can name a sheep "jeb_" and it turns rainbow.
All in all, I added a wool block that does the same.
Here's the recipe:
[dark blue wool] [light blue wool] [green wool]
[purple wool] [name tag] [yellow wool]
[magenta wool] [red wool] [orange wool]
And to make things even easier:
 [ink sag] 
[paper] [paper] [string]
  
I created the animation with a script.
If you have any ideas that I could ad-please contact me in the comments.
I hope you enjoy this mod 😀