I on my iPhone 5s and close it gain and the screen starts fading away in a purpleish black colour?

I on my iPhone 5s and close it gain and the screen starts fading away in a purpleish black colour?

Added (1). I open an app*

That's because of water moisture, the only solution is to keep it in the container of rice for around 2 to 3 days and for securing your device, Leo Privacy Guard would be the only solution as it grants you many security functions and keep your device utmost secure. Also know this, that it is the world's top ten apps.