03-02-2021, 08:57 PM
Is you image color-indexed? If so you have purple corners in the FG/BG color swashes in the tool box, telling you thathe colors are not usable in the picture.
When an image is color-indexed (all GIF, and some PNG) the colors of pixels are encoded as an index in a colormap, and the only color you can use are those in the color map (otherwise Gimp tires to find the nearest color).
You can change your image to RGB using Image>Mode>RGB.
When an image is color-indexed (all GIF, and some PNG) the colors of pixels are encoded as an index in a colormap, and the only color you can use are those in the color map (otherwise Gimp tires to find the nearest color).
You can change your image to RGB using Image>Mode>RGB.