How do i remove my coloured name?
And how do i remove coloured names for someone else?
Is there also a way to give someone else an gradient name colour? So they pick 3 hexcodes i fill them in and give it to them? Or do they need acces for that?!

/colour reset
For others you currently would need to delete them manually from the datafile.
Will be implementing some sort of system here though soon

Merged post

Complety reworking how the command works fits it better

Merged post

You can now execute any command from either server console or player on any other player via using /colour set <playerNameOrId> ... - more info can be found in the documentation! Hope this solved your issue for you