• Incomplete file transfer: Sometimes, you need to transfer photos from one device to another. If the gray pictures that you see are the ones you have transferred from another device onto your iPhone, there is a high possibility that it might be due to incomplete file transferring between the two devices. It could happen during the abrupt power shutdown or internet outage during the file transfer process.

  • Damaged or Corrupt Files: Corruption of photos present in your iPhone due to corruption of Hard drive, memory card, etc.

  • Unsafe Photo Recovery Tool: There is a possibility that you might have used some unsafe photo recovery tool. As a result, this could result in corruption and thereby greying of photos on your iPhone.