That was my concern too.
What little research I've done regarding the white vrs. pearl is this:
I think Niemans has this bag exclusively - In white. (unless it was Saks, one of the two.) ebay has them too - but don't now where they get theres.
Well you know Isabella makes her bags in various colors and distributes them all over the place, Anyway the VERY popular website that carries the line in hawaii @adasa.com w/ a large selection shows it in the Pearl you are talking about.
So after researching as many places I could that had QUILTY Pleasures they were the only ones you could pre-order it in Pearl. Arriving Mid-March. I was told from ICE ACCESSORIES BOUTIQUE, It is the best place to shop for her line. They also told me she does a limited additon of 300-350 each bag, I don't know to believe that applies to all.
I Want to order this bag NOT IN WHITE, But in Pearl so bad but had the same concern as you. I WANT THE PEARL!!!! AND THE BROWN!!!(Shown on adasa.com)go check it out.
These are not facts, just research I have done. IF I am wrong about any of this please let me know. good luck!
ps I BOUGHT 2 FIORE BAGS TODAY!! "Stud Muffin" Carina in Bone and Carina in Caramel/Tan Hobo.