Hi, I recommend getting the Nametags plugin, what this does is give's everyone a coloured username. So for default's they could have a green username and a green nametag. And the donators have their's set as their ranks [ ] colour. It'd defiantly brighten up the server a little.
Unless it allows us to bypass the 16 character limit, it won't be added. Don't want it to look like this: https://www.minetime.com/threads/hub-tags.950/
It only makes their username colourful. The idea was that the colour would be the colour of their ranks []. An example: https://imgur.com/a/dq8G3
A good plugin for this to include colorful names and ranks would be: https://www.spigotmc.org/resources/nametagedit.3836/ since it bypasses the 16 character limit. @xBMAN