Because I am sure you want to know, here’s a short explanation of what “off road diesel” is.
“Off road diesel” is diesel that is for use exclusively for off road uses. Like farm vehicles or diesel generators.
It’s dyed (red, usually) to distinguish it from non-off-road diesel. It’s cheaper than regular diesel because its price does not include federal highway taxes. And, while you can burn it in your diesel car, for example, without harming the engine, you’ll be risking some tax evasion charges.
If you want more information – and who WOULDN’T want more information?! – you can go here.