The palette shift is an artifact of the current dithering (quantization) algorithm [1]. It becomes visible when you apply quantization a few times to the same

The palette shift is an artifact of the current dithering (quantization) algorithm [1]. It becomes visible when you apply quantization a few times to the same image. (50 in the example. I've updated the image and replaced the "After" label with "Gen 50" to make this more obvious.) It won't be too visible to the human eye after a single quantization pass. Edit: The result of a single pass for the anime image looks like this: https://i.imgur.com/dTmzRwF.png https://i.imgur.com/dTmzRwF.png. I've changed "visible" to "too visible" above, because the image is visibly a little brighter. [1] https://github.com/dbohdan/hicolor/blob/f00eac41417b0e989e1e4363393994a1c7a02939/hicolor.h#L282 https://github.com/dbohdan/hicolor/blob/f00eac41417b0e989e1e...