ha ha, I actually had this bumping around in my head when I was thinking of methods to do it, except I didn't have the dll part.
Thanks for doing this, at least. In a couple months, after I've gotten some mastery of rgss, I'll be able to inplement it in chapter two. For now, I'm just using an actual screenshot and inverting it, which is time consuming and space consuming, but oh well.
Thanks for trying.