Unplated is just that - the real colour of white gold, before the (usually final) rhodium plating procedure.
Different wg alloys will have slightly different tints - range from v. white to quite creamy, so you'll want to do some investigating re. what exactly you're looking for.
ETA past my edit window but I also want to add - my Ering is unplated wg (nickel alloy, quite creamy/yellowy).
You may want to seriously consider having your wedding ring made at the same time, as even slight differences in alloy composition will create different colours (not all 18k Ni-wg looks the same!). I am myself learning that having a matching wedding band made to match exactly in colour after the fact can be an expensive undertaking.