Jamba, the conclusion.
Well, the quest for the secret Jamba menu is apparently at an (unsatisfying) end:
A Jamba Juice manager (!) sent me the following:
Hey I work at Jamba and I have to tell you we don’t actually have a “secret menu” per se. Every store is different, and every store has different things we can make, but most of the recipes we just know in our heads and agree upon in general consensus. The white gummi is one of those drinks, although there are at least 2 official variations (They’re supposed to taste like different flavors of gummy bears). The starburst is almost the same as gummi bear, except for we use Lemonade, not soy and peach.It still has all the sherbets in it, plus one green scopp of peaches. I’m not a big fan of it, but we get orders for it every once in a while. The best way to find out a store’s specialties is just to ask the stores employees. Some stores make up their own secret menu. For instance, our store started one called the Peanut butter and Jelly, and other stores have gradually adopted it. And that’s pretty much how it works, nothing official like In n’ Out.