I have a MacBook Air 13 inch laptop since 2011. Quite recently the screen had problems. It start flickering, changing colors, and vertical lines appeared in the middle of the screen. All these are starting when I move the screen backwards, forward or when I am lightly pressing with the fingers the top of the screen. This is also the only way to re-adjust to normal operations. Any recommendations?
These symptoms all point in the same direction, there are some hardware issues. Perhaps a loose contact somewhere, moisture on the main board or display controller, etc. The fact that they happen or increase when moving the screen further back, all just add weight to the above analysis.
Your best bet is to take your laptop to an Apple Store or Apple Service Provider and let them have a look.