1. If you purchased the phone from Verizon, you would need to do any "exchanging" with Verizon.
2. As noted above, you can only exchange with in the first 14 days (counting the purchase date) and there might be a restocking fee.
If it means that much I would exchange the price Is 35$ worth trying to ask for a waiver but unless it's on promotion ask on the phone w customer service but the 35$ restocking fee will apply.
I wouldn't bother unless the change was more for front (Black for white or vice)