I think I might like the look of the grey wheels more than the silver, but it seems they're not an option on the 40kWh.
My car is not a signature, and the grey wheels were an option. I don't see why they wouldn't offer them on any Model S.
They are only an option to come on the car if you get the performance model, I think.
However, they also sell them via the Tesla Store online. So if you get the 19" wheels it appears you could then buy the grey 21" wheels after your car arrives, although I haven not heard personally from anyone who has donee this to confirm it.
I tried the designer, and Ceilidh is correct. They are an option on performance models.
Ceilidh is right. TM will only deliver perf cars with gray 21's. You can however purchase them from the online store. $3,500 for just the gray wheels or $5,200 for the wheels & tires.
You can order the rims and then just go by the tires yourself afterward.