If it looks correctly if you load them unchanged, then there should be a way to edit them. The format needs to be exactly the same as you dumped the image.
I think you should only change it, using exactly the same color values as the image already uses. That's the only way to know which color should be which. Also, you must not use a value outside of the used min/max values, those might be completely undefined and use memory from something else than the palette.
I think you should only change it, using exactly the same color values as the image already uses. That's the only way to know which color should be which. Also, you must not use a value outside of the used min/max values, those might be completely undefined and use memory from something else than the palette.