The outermost zone is the blue zone ... But here the innermost zone is regarded as the blue zone ... I am getting confused ... Please explain ... Thnx in advance :)

Dear Student,
The reaction that takes place when we light a candle are:

1. Heat of the flame vaporizes the liquid wax (turns it into a hot gas), and starts to break down the hydrocarbons into molecules of hydrogen and carbon.

2. These vaporized molecules are drawn up into the flame, where they react with oxygen from the air to create heat, light, water vapor (H2O) and carbon dioxide (CO2).

If we closely look at a candle flame, we will see zones of flame.

A blue area at the base of the flame

Above that is a small dark orange-brown section

Above that is the large yellow region

The oxygen-rich blue zone is where the hydrocarbon molecules vaporize and start to break apart into hydrogen and carbon atoms. The hydrogen is the first to separate here and reacts with the oxygen to form water vapor. Some of the carbon burns here to form carbon dioxide.

The dark or orange/brown region has relatively little oxygen. This is where the various forms of carbon continue to break down and small, hardened carbon particles start to form. These carbon particles along with water vapor and carbon dioxide created in the blue zone, they are heated to approximately 1000 degrees Centigrade.

At the bottom of the yellow zone, the formation of the carbon (soot) particles increases. As they rise, they continue to heat until they ignite to incandescence and emit the full spectrum of visible light. The soot particles oxidates near the top of the flame’s yellow region (with temperature, 1200 degree centigrade).

The fourth zone of the candle (sometimes call the veil) is the faint outside blue edge that extends from the blue zone at the base of the flame and up the sides of the flame cone. It is blue because it directly meets with the oxygen of the air, and is the hottest part of the flame, typically reaching 1400° C (2552°F).

Hope it helps.
Regards.