You can set the help text in the config, as well as the list of worlds that this plugin will work in. Not everyone uses the default naming structure (world_the_end) and some servers have more than one End Dimension. This allows you to control where it does and doesn't take effect.

Defaults set enable to true, worlds to world_the_end, and the help text to:
"To change the color of a shulker, hold dye in your main hand and right click on the shulker. To remove the color, use a wet or dry sponge in your main hand and right click on the shulker."

Commands
/colorshulkers
- Outputs the help text which is set in the config.yml file

/color shulkers enable (true/false)
- Quickly enable or disable the plugin with this command

/colorshulkers reload
- Reloads the config file

Permission
colorshulkers.help
- Enabled by default, for viewing the help text

colorshulkers.enable
- Op by default, allows enabling and disabling the command

colorshulkers.reload
- Op by default, allows the reloading of the config.yml file