Does Resprite support Indexed color?

If you want a real indexed color image supporting, the answer is NO. The indexed color tech is in order to save file storage. But that's not important today, because storage is cheap.

If you want to replace color by change palette's color, the answer is YES. We have a checkbox "Like Indexed" in Menu->Palette, when checked, change to palette color will automaticlly change the relative pixels in canvas.