The notification area shows you the last five and most important messages, you´ll want or need to read. The colour shows the message type. On the top is the sixth neutral message, that is used for general information. Magenta: This is a level based notification if you earned experience, a level or a skillpoint (For Example) Red: Negative message, when a wave spawned or the protectbase gets attacked (For Example) Green: Positive message, when a building is built up or something crafted / finish / upgraded (For Example)
White: General information about In-Game progress or tips / hints. After a new message/event comes in, the oldest gets removed. Every message is shown with the gametime stamp so you can see, when the event happened. Every message will be saved into the history log that can be viewed after finishing the match.