I too had this problem since last 1.5 years.. somewhere I read online that you can get rid of it by placing your cellphone in freezer for sometime and it will get rid of the pink/purple issue of camera. So I did it.
WHat to do-
1.) I placed my cellphone HTC One(M7) in my freezer nicely wrapped in a small towel
2.) changed my refrigerator setting to the coolest...
3.) kept it in there for almost 20 minutes
4.) Took it out.... and no more Pinkish pics.......
Not sure if its permanent solution as I have tried it today only.... but as of now I am happy to see my camera work as good as new.... NO FAULTS WHATSOEVER.