After giving up on trying to figure out how to get my Surface Pen to work again, figured I'd conceive of a troubleshoot-proof method to get some digital coloring done.
Blocking out color fields on separate sheets of paper with the aid of a lightpad. All in black markers, a kind of manual color separation essentially. I scan those in and apply the appropriate color to them in Photoshop. This works for me because I tend to go for a “graphic designy” approach to colors with very limited palettes.
It's a couple steps slower than working directly on screen, but better than having to troubleshoot a bunch of tech nonsense for hours on end and still not get anywhere.
In other news, found me some of that Moebius/Superstudio-lookin' gridded wallpaper, and maaaaaaay be tempted to scoop it up when/if I cease to be terribly poor.