How can a colorless fuel be identified as diesel or not?

A colorless fuel can be identified as diesel through several methods. One common approach is to check its density and viscosity, as diesel typically has a specific gravity between 0.81 and 0.87 and a viscosity of around 2-4 centistokes at 40°C. Additionally, a simple distillation test can be performed, as diesel has a distinct boiling range between 180°C to 360°C. Lastly, conducting a flash point test can determine whether the fuel meets diesel's flash point criteria, which is generally above 55°C.