I have an XPS 8930 and for some reason, any gray colors are comprised of tiny dots that move around like ants.
I think it may have started when I installed DCS World (flight simulator).
It sounds like a screen resolution setting. Make sure you have the correct setting for your monitor. Also try updating your video drivers. The following site has suggestion regarding Windows troubleshooting.
Delete everything pertaining the flight simulator to see...…….
VGA vs DIGITAL color depth 24 bit or 16 BIT or 8 bit.
Older Directx9 is not going to be directx 11 or 12 at 32 bit color.