Are carrots DYED to cover up the dirt on their skins ?

Although I usually peel carrots, occassionally like the 'earthy' taste of unpeeled carrots and potatoes with a roast. I bought a bag of bright orange, very clean-looking carrots and scrubbed them under running water to hopefully remove some of the chemicals and bacteria that might be on the surface. Each and every carrot turned 'dirty' as if I had removed some sort of coating/dye/paint that was covering up the natural dirt they grow in!!! Is this possible? I know certain fruits & vegetables are coated with an oil to make them shine, but a dye to cover dirt on carrots ?? I can't find any info on searches about this. Anybody know?
Of course I'd prefer organic but I can't afford it.