Why is my screen turning rainbow on s4 zoom

[AC Question]

My phone isnt working as well as it has in the past. Its over 2yrs old.
Cant sent txt messages
Wifi never connects
Battery dies VERY fast (replaced it and same thing happens to the replaced battery)
Touch screen works on and off and now Im getting a rainbow screen.
What could be wrong?

 

[belodion]

The rainbow effect could be a Daydream feature.
It sounds like a Backup & Reset might be worth trying. Let us know if you need advice about that, especially about backing up fully. We have ready-written Ambassador Guides.