Chosen Solution

I dropped my phone on a tile floor and when I picked it up I noticed that the overall screen was darker. I tried turning my brightness up and down but it didn’t work, I also tried changing the colours like inverting them and Turing on grayscale but it didn’t work. Please help, it would be appreciated.

I would say there are two possibilities.

  1. You damaged the screen back light when it was dropped.
  2. You damaged the back light IC on the iPhone. First, I’d purchase a 5c screen here from iFixit and see if that fixes your issue.

Try to re-seat the connectors, maybe the LCD cable got partially disconnected.