Final answer:
A 'non-luminous flame' is typically blue, indicating complete combustion with a good oxygen supply and high temperature, as seen with a Bunsen burner.
Step-by-step explanation:
The term 'nun luminous flame' appears to be a mistyping or misunderstanding, possibly referring to a 'non-luminous flame' which is a terminology in chemistry related to the type of flame produced during combustion.
A non-luminous flame is typically blue and is the result of a complete combustion occurring at a higher temperature with a good supply of oxygen which allows for complete oxidation of the fuel. In a laboratory setting, this type of flame can be observed with a Bunsen burner adjusted to provide the right mixture of gas and air. The blue flame is characteristic of the complete combustion where the gas reaction with oxygen produces carbon dioxide and water vapor