Well, they are both distilates of crude oil, and both release a similar amount of heat when burnt, (about 40Mj/kg). In England Kerosene is called Parrafin, and is now only commonly used domestically in things like greenhouse heaters. Its greatest use is as a fuel for jet aircraft engines. So called "red" diesel is so called because it is dyed red to distinguish it from diesel you would buy from a filling station to put in your car, it is sold to farmers for tractors etc, and carries a lower tax value from the inland revenue, so it is cheaper, so the colour just allows the police to detect if you have been putting it in your car instead! Not sure about your genny though, diesel ignites when compressed, ie without needing a sparkplug, im not sure if parafin would do the same, I would have thought not. I would suggest you ask this question on the science page on this site, someone more knowledgeable than me will be sure to be able to tell you!