I have a 4 year old xps m1530 that has been having screen problems for almost a year now, which unfortunately started a few months after warranty ended. Basically, the screen will suddenly go negative or sometimes it will head towards gray/white. The way I have been dealing with this is by 1) applying pressure around the edge of the screen or 2) lightly hitting the right side of the screen. While this (horrible) solution works 95% of the time, the screen will sometimes go completely white, at which point I have to sleep/restart the system to have a hope of restoring the picture.
This occurs randomly for the most part, but motion of the screen/laptop can also trigger this problem. At this point, I have ruled out the video cable as the source of the problem. I guess I just have a faulty screen?
Welcome to the Community. Have you tried reseating the LCD flex cable? Use the below link for help. If this does not work then you may need a LCD replacement.
I actually purchased a new LCD flex cable and replaced the old one, thinking this was the problem. Unfortunately it took the $40 purchase to rule out the cable. It is just frustrating because the screen was replaced in the last month of my warranty, and began having problems within a few months of installation.
Try connecting it to an external monitor and see if the problem is reproduced there. If it is not, it's your LCD. If it is, it's your GPU.