Back in the day when I was working as a power equipment engineer, one of the major manfacturers of large stationary diesel engines used in generators made noises about not honoring the engines' warranty if anything but no. 2 diesel was used. The no. 2 diesel could be red or any other color, but not clear like no. 1 diesel or kerosene. They said modern diesel engines require the additives in no. 2 diesel.
As an example a customer had an installation with a pair of turbines (jet engines) with an 18,000 gallon tank full of no. 1 diesel. The customer wanted to replace the turbines with new diesels and reuse the tank and the no. 1 diesel. The tank had passed all of the regulatory hurdles and the customer did not want to redo.
The compromise was that the customer would continue to use the existing tank and fuel, but that all fuel added in the future would be no. 2 diesel (red). It would take years for the diesels to use all of that fuel with only normal maintenance runs. During a hurricane or some other major power outage the fuel could be used within a few days. The tanks were sized for 72 hours at maximum output. For equal KW output diesels use about half as much fuel as turbines.