You just change the next box to not allow the driver to override the banner. Properties > Services > Printing > General
As for color control, either use XSA to only allow specific user accounts for color, or just make anyone who is not logged in totally lose that ability entirely via:
Properties > Login/Permissions/Accounting > User Permissions
Select the Edit for User Permission Roles
Select Edit for the Non-Logged in users
Then simply lock them out.
But, please, make absolutely certain all your users know what you did and to not call Xerox because "They can't print in color". If they don't know, and they call Xerox, there is at least an 80% chance a technician will come on site and wipe the device, this should not happen, but it does, and the reason is that changes like this are made without the end-user being aware, and the end-user calls Xerox, and since Xerox is left troubleshooting a "Worked yesterday, doesn't today, nothing has changed on our end" call, the device gets wiped.