Change colors to your GIFs instantly, with GIF Palette Changer
GIF Palette Changer is a freeware utility that will let you modify quickly a pallete of any GIF image.
It lets you select and modify colors. You can change Hue, Saturation and Light.
If you need a quick and basic transformation of a gif image, e.g. colorize it from blue to yellow tones, etc., this utility might help.