I dunno if it's any help at all, but I can second what Tim has said. I don't have personal experience with this change, but have read about numerous separate accounts of it happening. In some, it happend gradually over 2-3 sheds, and in some it happened all at once like with yours. In each case, there were no ill effects to the snake at all, and it returned to its normal color within a few months and a few sheds.

Absolutely stunning spider you got there...both in her usual "wardrobe" and in her new outfit! Her and that beautiful pastel are gonna make some smokin' bees!