12-14-2020, 08:16 AM
Are you editing the color-map or the image? In color-indexed mode a pixel value is just an index to a color in the colormap. When you can change the color on the pixels (paint...) they are adjusted to the nearset color in the colormap. Conversely, if you change a color in the color map, all the pixels with a color index that points to that color have their color changed. You can edit the colormap with Windows>Dockable dialogs>Colormap