Purple coloured desktop screen

Hi, I have a Acer Aspire ES 15 laptop, running xubuntu 20.04. Normally I see the usual colors used by xubuntu at start up, and I have a picture of a sunrise on my desktop. One week ago I start up to a purple screen and I login and it remains purple, which makes it hard to see my desktop clearly, and if I leave the desktop idle for a while the screen seems to memorize what ever I leave on the desktop causing line prints. The first time the screen became purple it corrected its self a few minutes after. The second time it took longer, maybe 10min. The third time it went from purple to light blue, and I could see a pink line around the edge of the screen. But now purple every time. Everything else seems to work ok. Any help would be appreciated, thanks in advance.