It's not a disappointment, I was just wondering. "Chocolate" leucs are a result of a specific genetic mutation from a group of the "standard" leucs in the hobby, but I had not heard of this particular mutation happening within the lines of banded leucs, which is why I was asking. It certainly could be, I just don't know for sure one way or the other.
To the OP: the yellow vs. orange is just a natural variety, the same way some azureus may be lighter or darker shades of blue (and I'm not talking about the ones bred for "sky blue" lines...) My leucs tend to come out rather orange compared to some people, and I think it may have something to do with what I feed the tadpoles since the ones that develop in the adult vivs and eat ff, algae, detritus, etc. come out much lighter yellow. Some tend to fade to a more yellow color, others keep the orange through adulthood. I do not supplement with color-enhancing supplements often at all, maybe once every 2-3 months.
I just got a clutch of 6 eggs from my leucs this evening, maybe I'll check what kind of color variation they have when they morph out if I remember.
Bryan