Click on the My Fleets option under the My Account Section to get to the Fleet Management page.
Click on the SETTINGS tab to define your preferences.
The "Add/Delete notification when adding/removing a new vessel in/from my fleet" options enable you to define whether vessel-based notifications will be automatically created/deleted every time you alter the composition of your fleets. Keep in mind that you can change your preference per case, when adding or deleting those vessels, without affecting the above settings.
Note that if you have enabled Fleet Colours, you will also be able to define a colour for your fleet.
It allows you to be able to view the vessels of your Fleets on the Live Map with distinctive colour markers surrounding the vessel icons for easier identification.