AVGAS is the most commonly used fuel for piston engines. Some gas turbines can run on AVGAS but it is not the fuel of choice and is normally only used in the case when kerosine or jet fuel is not available. AVGAS contains a highly toxic lead additive in order to achieve high octane ratings and is coloured according to the grade. For example, 100LL (low lead) AVGAS is dyed blue.
The blue dye in the taken fuel sample indicates that this fuel is 100LL
Within Europe, for reasons of cost and environmental concerns, there is a move away from AVGAS to jet fuel with more and more light aircraft being fitted with highly fuel efficient diesel engines.
AVGAS is not to be confused with AVTUR (Aviation Turbine Fuel) or AVJET which are jet fuels.