I am planning to develop an advanced chatting system

Question

hello... I am planning to enhance my Simple Chatting System that is shown in the Networking part for the C#. My enhancements will be colored texts, allowing the user's to create rooms, private chatting and file sharing. But I did'nt get the start point for doing that, So I will be happy if we open a disscusion for these enhancement, and the dis. will be on HOW TO : 1-Allowing users to create their own rooms. 2-Coloring text, So , each user can choose the color that he wants. 3-Allowing two talkers to talk to each other privately. 4-finally, Allowing to share files . waitting for a hot disscusion... :)