I think the gray is kind of nice, actually. Maybe put gray on some part of the bat boots as well (the bats?). Alternatively, you could actually try matching the blue on the skirt. I have yet to see anyone do that successfully. Dark blue top, dark blue bats? If you go for the gray, though, make it a bit darker. Iffy on the mask. It looks a bit strange. Same for the gloves. They clash with the clothes a little, right on the edge of the sleeves. Not really a big deal though. Just a minor thing.
I found it kinda funny that two people complained about the undyeable part. That would mean he had four colors on it, and that he was a haxor D<!