I recently purchased Might and Magic 1-9. They installed just fine, but when I try to open any game, it says that my computer needs 16 bit color. I have Windows 10, though, and I can't find where to change to 16 bit. Is there any way around this?

By the sounds of it you are trying one of the early games. If so you need to make sure you run it through DosBox, you can't just find the executable and run it directly. If you are using DosBox then you might need to look at the DosBox configuration and change some settings.