My temporary implants are grey. Is that normal? (photo)

There are a few ways to improve this and none of my patients would ever accept this even temporarily as they would question my ability to finish the case satisfactory. Motivate your dentist do better as it obviously bothers you and I am sure they can improve as we all like happy patients that brag on our dental work. 

Your final crowns won't look gray. The gray is caused by a metal post holding your crowns to the implants. The implants are not causing the grayness. You can ask your dentist if he will change out the metal posts for tooth colored plastic posts. This will correct the grayness that you see. Good luck! :)

No worries! Your grey teeth are like that because there is a metal piece that goes into your implants which hold in the temps. That metal is shining through the plastic. It won't be like that when the crowns are completed. 

Without an X-ray this is an educated guess.  I think the temporary abutment (the part that inserts into the actual implant) is gray metal and the actual temporary material for the crown is too dark and too translucent.  
I agree with you.  The crowns can be made to look much better.  I would talk to your dentist and tell them that your need these to look like your other teeth and have them redone. I think these should look as close as possible to your final crowns to make sure you like the size shape and color. Once you like that your dentist just duplicates that for the final restorations.

I believe you are speaking of gray implant temporary restorations and that the implants themselves are not temporary. The temporary restoration (provisional) on the implant might be made of Titanium and with thin restoration material, the color can appear grayish. Your dentist may choose a white temporary abutment (temporary abutments) and a provisional with corrected shade match to improve it. Otherwise you can wait for the final restoration which can be made completely from ceramic material as guided by your aesthetic needs, tissue thickness, occlusion (bite), etc.I hope this is helpful.