Notes (including the colors) are stored in your database and associated with the players the notes are for, so if you were to wipe everything there would be nothing to associate the notes with so the notes would also be removed.
You could export your notes (using Database > Notes in the menu) and then import them to a new database, but if you haven't imported any hands into the new database then there would be no players to associate the notes with.
You could create your new database (using Database > Database Management) and then when you've played you could import your notes, but that would only work for players that you've met in the hands which are in the new database.
Rather than wiping your database you could use filters to see only your recent data, and in the Hud you could use the 'last X weeks' optino (Hud > Edit Hud Options) to only see recent stats on your opponents.
To open a
Support Ticket click here. See the
Tutorial: Reporting a problem for information on creating and finding log files.