Different types of fuel that burn in bushfires, results in different colour and density of smoke, illustrated by Figure 4. The paler the colour of smoke, the moister the fuel. This also means that the fire is less severe. If the smoke is dark, the fuel will be dry and the more severe the fire is. The shape of the smoke also indicates the speed in which the smoke is moving. If the smoke is thin, that means the fire is small, while thick smoke means the fire is speeding rapidly. These indicators can be helpful to fire fighters as they can assess how serious the fire is and how much time they have to respond.