Feature request

Feature description

Allow blocking specific color codes in many places, such as signs, nicks, chat, etc.
How the feature is useful

Allows us to block color codes we don't want users to use, such as black, or dark blue.

This is already possible for both chat and nicks, as far as I know. However, I don't believe it's possible for signs (yet).

To block a certain color code (e.g. red) from being used in chat by a certain user, you can negate the permission essentials.chat.red.

Similarly, to block a certain color code (e.g. aqua) from being used in nicknames, you can negate the permission essentials.nick.aqua.

You can find a full list of the color names here.