IPhone issue help

[Mattk13]

So... I have an iphone 5s and its got a weird issue where when you first turn on the display from not using it for 15seconds to 1min or more it gets a green color forming around all corners of the screen then disappear after a few seconds but it has gotten worse where its always in one corner of the screen looks something like this i can't take a picture as its my only phone but it looks like this but less intense  This is what it looks like without the blue and black and more in the corner and not so big is this a screen issue or a hardware issue

as in i would need to replace the entire device

screens cost 55 bucks just wondering whats wrong with it

[Uptivuptiz]

Could be water damage. Haven't seen anything like it. Maybe the connector for the LCD panel is breaking. Either way it would be a good idea to replace it