To take the colors from one image and apply them to another, the following approach yields the best results:

1. Open the two images
2. Set the focus to the target color set and save the palette. Colors > Save Palette. You may have to convert the source image to a .gif for this to work.
3. Set the focus on the image to be recolored and load the saved palette. Colors > Load Palette

Bear in mind that if you have alot of images, you may want to pursue batch processing, either through the GUI, macros, workspace, or command line options.

This approach will probably work for any powerful image editing software, however, its success is dependent on the images and colors involved. Not all images can easily be recolored.