Below is a comparison picture of astromech droid R2-B1 from the 2012 Walmart exclusive "Royal Starship Droids" battle pack.
The first figure was released with an unpainted blue dome interior this was corrected by Hasbro later on to a silver painted interior (just like all the other astromech droids in this set).
Left corrected version | Right first version
Astromech droids repair the Naboo Royal Starship. The shield generator and hyperdrive are damaged while escaping the Trade Federation's blockade of Naboo. The droids fix the generator, but the hyperdrive is too badly damaged. The ship is forced to land on the remote world of Tatooine to find a replacement part.