If you google "purple tint" or "camera problem" about HTC one M7, you will be surprised how many people had this problem. After a google survey, was revealed that over 364 devices of 500 had this problem. The difference until 500 There are devices that still have problem but not so noticeable.
It happened that I got in possession of one of this devices, with severe purple-pink color on display when camera it is on, indoor or in low light places. I haven't noticed anything wrong with the camera before night came, same day I bought the phone.
I was comparing camera side by side with a Nexus 5, when I started to see some purple on the down side of the HTC one, where the touch arrow and home button is. And then the research started. Read more:
HTC ONE M7 CAMERA FIX (PURPLE-PINK IN LOW LIGHT)
First of all, camera during daylight works perfect, even if HTC one's aluminium body it is so hot that it hurts my hand. Here are some examples of photos, that I took while the "problem" was still persisting even inside a car in daylight and as you can see there is nothing wrong with those pictures:
Second, I tried lots and lots of pictures, in a variety of situations before the conclusion.
Picture 3 was taken with auto focus and flash before fix and picture 4 was taken with manual focus and flash before fix, both indoor with no light.
The screen was full pink before I took both of pictures. The difference is that in photo 4, I pressed many times on manual focus and moved phone forward and back until I was able to see the object focused behind camera. In photo 3 I just took the photo with auto focus.
So the problem it is not high temperature! You can see a nice and clear picture in the right side.
So I went to the next step.
I took one more picture with flash on, close objects and "finger focus", manual (photo 5). The result is amazing. The only light was the light of my monitor that is not counting because it doesn't help.
AND THE MOMENT THAT WE ALL WERE WAITING FOR:
Custom [ROM] ROOT