One of the easiest ways to identify a YB (usually) is to post a belly picture of the BP in question. If you can get a picture of the "normal's" belly, that might help.
As for the Pastel being a Blonde or not, who knows. Blonde Pastel is just another line, as are Graziani, Lemon, etc. The only way to really tell what particular line the Pastel came from would be to trace its lineage.