That is a similar look that I am going for.. I was thinking about the tire paint, but like the pic you posted, they look more beige than white. I am not above using paint, but since I need tires anyways.... I have been to moped central, but they are out of stock, and have been for weeks. I just was not sure if someone else knew of any other shops.
I even went so far as to explore buying 16" x3" whitewall inserts and trimming an inch off the bottom to make them 17" x 2", but they have a molded lip to fit into a rim.