For a particular flight the flight path is shown predominately as white but some sections of the flight are shown in green. What does the green mean? See SIA308 13-AUG-2014
This should answer your question, flightaware.com/about/faq#mapPlot. The white line is basically estimated position while the green is when the aircraft is actually being tracked.
This is a somewhat common question. Perhaps a legend could be placed near the map?