I think that will only be possible if there’s an option in the game’s settings. Or maybe a tweak to the game’s config file (an .ini / .cfg file or something like that). I find it a bit strange that this game needs 32 bit graphics though, all this pre-rendered stuff can’t have more colour depth than 16 bit. At least judging by the sceenshots I’ve seen.
Edit: wow, I’ve checked the system requirements, and it does indeed say “24-bit PCI card with 2 MB RAM (4 MB recommended)”.