Any time I try to load this game I get a message about "requested resolution of 640x480 not supported by DirectX driver, falling back to 640x480." I then press okay to get a message saying "Sorry, this program requires support for 16-bit color mode."
Does anyone know how to fix this?

If it's still a thing (and for everyone else stumbling across this): For games from that era use dgVoodoo2, which emulates a card compatible with the ones from that time, including 16 Bit color modes.
Modern drivers often lack these modes.