No way of updating the colour of a role

[jesyspa]

As it is, once a role with a particular colour has been created there is no way to use that role name for a different colour, even if the old role is not used A few ideas for how this can be resolved:

1. When clearcolor is used, check if no user has the role and delete the role in that case.
2. Allow setcolor to update role colours when the role already exists.
3. Add an changecolor command to modify the colour associated with a name.
4. Add an deletecolor command that removes a colour role.

I'm not sure option 1 is feasible, since I don't know if Discord has a way of easily checking if a role is unused. Options 2-4 all seem like they would be reasonable solutions. I'd be happy to give implementing one of the four a shot; does anyone have a preference on which one? (Assuming this is a desirable feature in the first place.)