Ive got a bunch of sprite sheets, but they have a white background. If I want to use them without the background showing up, the background color must be pink(255, 0, 255). How can I edit a sprite sheets white background to a pink background without effecting the actual sprites? Is this possible in MS paint and how?

Yes, you can use the fill tool in MS Paint (looks like a paint can tipped over with some paint falling out), and select the pink color and fill the outside. A problem may come if any part of the original image's edge has the same white color the background does; if so, the image will look funny.

I'd suggest you try it anyway, see what happens.