If you buy from a breeder that you can trust, they can tell you what line your pastel is coming from, and help you choose one that will be more likely to hold its color than another. Not just anyone will do that, though. A lot of folks who jumped head-first into the "morph game" are just trying to make and sell as many pastels as they can without regard to quality or "line." And, if in the unlikely event that you actually find a pastel for sale in a pet store....I wouldn't trust them to know anything about it any farther than I could throw the manager.....unless it's Zoo Creatures in NH. You could buy a killer pastel from them, I imagine.