ANSI (American National Standards Institute) colour is a standard used to transmit codes which indicate colours. With it on, you will see some things in Lusternia displayed in colour. Type ANSI ON to turn it on, and ANSI OFF to turn it off again. If you see strange characters when it is on, it means that whatever client you are using it not Ansi-compliant. In these cases, just turn it off again with ANSI OFF.

You can further configure what colours you will see various types of communication in by typing CONFIG COLOUR and following the instructions from there.