SilverStone ships the Alta G1M in a full-color package intended for both the black or white variant. On the sides are additional details and a sticker with a large B for the black variant inside.
Two foam spacers hold the case in place, with a plastic bag keeping away fingerprints and the likes.
There are not a lot of extras inside the case, consisting only of black screws and a good number of zip ties. That said, you don't really need anything else. SilverStone does not include a printed manual, so the only paper you will find is a warranty pamphlet. A QR code on the exterior packaging will take you to a digital copy of the manual instead.