Edit: Somehow I forgot to mention that the sprites on the left (top for the recolors) are the 3-bit ones, and the others still use a pretty restricted palette, but not 3-bit.
Another edit: Wow, another thing I forgot. Anyway, the “intended use,” for lack of a better description, is, going from the first row to the second and then from left to right: Standing, stopping after running, two walking frames, two running frames, jumping, falling, kicking, using magic, two flying frames, and two “fast” flying frames. Of course, if something just doesn’t make sense (like a flying frame for the earth pony sections), it isn’t there.