It's not easy being green
For a while, reports were coming through of green-tinted photos when using the iPhone camera. This gave the appearance of shooting in night vision. Granted, the iPhone's primary function is not to be a camera. That said, you bought it and it should work until you break it on your own.
The most common cause of the green was the iPhone's automatic white balancing feature. Which means it's pretty simple to fix. You can color-correct the photos on your computer with whatever photo software you prefer. Or, you can turn the auto white balance off.