LG screen turn different colors with lines

If the phone is brand new there should be a 12 month manufacturer warranty on it at the bare minimum. You will have to either consult the documentation you received with the phone regarding a warranty service, or go back to the store that you bought it. Only go back to the store if it is a dedicated mobile phone outlet [don't go to a supermarket and expect anything after 14 days].

It sounds like there was an undue amount of pressure on the screen and part of the screen has broken or some of the connections for the screen have become loose.