"Fade" was a derogatory term used by Andorians to refer to those of their kind who were not considered Andorian enough, such as those with Aenar heritage or those who had "sold out" to Humans.
History and specifics[]
Late in the year 2370, Commander Ortees Sharad, shortly after arriving at Andor, was called a fade by a group of Andorians due to his Starfleet uniform. (TNG - Alien Spotlight comic: "The Old Ways")