Version 3 map detail

FlightAware ADS-B Flight Tracking
1

My upgrade to version 3.03 went very smooth. (No WiFi to configure) Three questions:

  1. What do the different colors of the aircraft represent? Altitude?
  2. Is there a way to reduce the map detail? It makes the background very busy.
  3. Will SW updates be automatic or must I issue a command? (via the command line)

Thanks,
Glenn