What is red-dyed diesel and how can it lower fuel costs?

Red-dyed diesel this week became the subject of President Donald Trump’s rally in Nebraska, as Washington battles to relieve surging energy prices in the United States ahead of the midterm elections.

Trump signed an executive order at the Monday evening rally, telling attendees it would allow anyone to purchase tax-free red-dyed diesel, a measure the administration estimated could save truckers over $100 per refill.