GIMP guide to fake Chromatic Aberration:
Open the Desired image in GIMP, select one of the color channels and deselect the others (lats say red), go to filters>blur>motion blur, select zoom, enable blur outward, choose something between 1 and 5 pixels, apply, select another channel and deselect the others, do the same thing with that channel but disable blur outward, apply
pic related is before
