I'm having this issue while playing GalCiv III where sometimes, out of nowhere, my screen will suddenly change to a solid color (I've encountered brown, red, and gray screens) and then I can't do anything.  Alt-Tab and Ctrl-Alt-Delete have no visible effect, and I end up having to manually restart my computer.  Updating my video card drivers didn't fix the issue.

I have an AMD FX-8350 8-core 4 GHz processor, a Nvidia GTX 970 graphics card, and 24 GB of RAM.  I'm running 64-bit Windows 10.  I'm wondering if it might be a processor-graphics card compatibility issue, but I'm not sure.  I'm also not sure how to provide more info, since it's a lockup instead of a crash, and the nature of the problem is that I can't do anything after it occurs.

Hope someone can find a solution (I've also posted a support ticket).