Can I trade my iPhone 5s white for a black one?

I'm with verizon. So I got the 5s white 3 days ago and I want black. It's in perfect condition. I'm using a case and screen protector. Could I trade it in at verizon or at the apple store?

Yes, you can. Verizon, like most carriers, has a policy where you can use a phone for up to 14 days before deciding for sure you want to keep it, though you'll probably have to pay a $35 restocking fee. Here are the details:
http://www.verizonwireless.com/...urn-policy

Or, if you don't want to visit the link:

Wireless Device/Accessory Return Policy

You may return or exchange wireless devices and accessories purchased from Verizon Wireless within 14 days of purchase. A restocking fee of $35 ($70 for netbooks and tablets) applies to any return or exchange of a wireless device (excluding Hawaii).

Exchange New Merchandise

You are permitted to make one exchange. To make an exchange, return the merchandise (including device, charger, battery, instructions, and any other components) in the ORIGINAL box. All merchandise must be in like-new condition and accompanied by the original receipt. Shipping charges may apply to exchange merchandise sent to you by Verizon Wireless.

Hope that helps!