enchi isn't the type of pastel your looking for, its a different morph. i believe epic is also, but im not 100% sure on that one.
and your answer is going to be, you have to look at the animal your buying, doesn't matter what line it is, or if it doesn't have a line at all. line is just a label, their all pastel and all lines have great looking animals and subpar animals. after seeing hundreds of pastels, I cannot say any line is better than another.
you want it to have the best chance of being bright yellow adult, buy a bright yellow baby and hope it holds it color. bout all you can do. focus on the animal your buying not the label put on it.