Not too shabby... it looks pretty retro, if you know what I mean, and I like retro. Some palettes look kind of eye-blending and/or slightly unpleasant, though, such as the Pokey's segments' palette (as already pointed out) and the sand palette in the same screen, which could have been smoother.
Aside from these minor nitpicks, though, I like it. I think I will actually give it a go tomorrow - never played the original version, so it is going to be fun trying out this new, improved version.
EDIT: Oh, wait, so the Pokey's palette doesn't exactly show up that way in-game? Well then, ignore my critique about it.