Hi Mark!
I don't know what you are refering to regarding the colours of the cranes, but I know that you can download new crane missions in the mission section on this board. There is one right here:
http://www.shipsim.com/ShipSimForum/index.php/topic,1339.0.html
Remember to register your SS08 licence key to you forum profile to access this section.
Regards
groennegaard