Plasti-Dip is great stuff. It's a spray on plastic paint that can be peeled off without any damage to the paint underneath. It's not good for the long run, but it worked perfect for seeing if I wanted to paint my tire rims white. Painted one, saw that I really liked it and then had to peel it off so I could paint all 5 rims with real paint.
I thought about painting the center cap black, like in the picture of the spare tire, but as soon as I put the back tires on I thought "VW Beetle". Not the right look for my Jeep. So I went back to all white. Looks great. I don't know if you can see the difference that well in the pictures, but the first one is original and the last one is with the white rims. That was my day today.