could there be a way to export a pallet as like an array, or have it write the hexcodes of each color on the pallet to a text file and then when you reimport it, it just plugs the hex codes in? I haven't delved into your code at all, so I don't know if this method could be implemented or not.
As for circles, I ended up just making it 31x31 and that way the sprite is centred. Not sure if this will pose any problems for me or not, as I've only worked with even pixel sprites, but I'm sure it will be fine.
One more thing, though, is it possible to change the default save location? I find it tiresome to browse every time I save something, when I'm always saving in the same place.