colour missing giving red and purple tinges

Couple of days ago the screen started showing red dotsand short thin lines over correct colours and now noticed purple and blue verticle lines where I would have expected blue. Have run a few scans and nothing showed and also restored to a few days before started. ( Kids use it and thought they may have had a go with the settings) Also checked colour settings and can find nothing noticably wrong Any idea what could be causing it and how I may be able to fix it. Appreciated

 

I'd start with a memory test using memtest x86. Sometimes faulty or dying memory can cause "artifacts". If you're unfamiliar with memtest, an alternative would be to plug in an external monitor to the VGA port. The end goal of this test is to rule out the internal display as a hardware fault. If the colours appear on the external monitor too, then you could try replacing the computers memory. If not, then you'll have to look at maybe replacing the LCD panel or the cable from the motherboard to the LCD. Cheers.