Your first glow

1. Give the colours out

A new player may open the picker and sees every colour, and may use the ones you granted. One node per colour, so a rank can carry two colours and another rank twelve:

lp group vip permission set uxmglow.colour.aqua true
lp group vip permission set uxmglow.colour.gold true
lp group mvp permission set uxmglow.colour.* true
lp group mvp permission set uxmglow.cycle true

There is no list of ranks anywhere in the plugin. It reads the node a player holds, and you decide which rank holds which node. uxmglow.colour.* works through your permission plugin's wildcard; the plugin itself declares it without children.

2. Try it as a player

/glow opens the picker: a free colour reads Ready, a locked one Locked. /glow set aqua skips the picker. /glow cycle red,blue,gold 400 steps through three colours every 400 milliseconds, /glow off stops, and /glow colours lists what the player may use.

3. Change the picker

menus/glow.conf is the window: the rows, the slot every colour sits in, the material of each square, the sound a click makes, and which lines of the language file each tooltip reads. Edit the file and run /uxmglow reload.

Delete the file and this server has no picker: /glow answers menu.missing in chat and every other command still works. A window is a file, so an operator can take one away.

4. Show it on a scoreboard

With PlaceholderAPI, %uxmglow_colour% is the colour's name and %uxmglow_tag% its MiniMessage tag: %uxmglow_tag%%player_name% writes the name in the glow's colour.

Related: Player commands, Picker