There is nothing special of the gold tint canopy in any aircraft. I am particularly talking about F-22 which is the one that people "discovered" the magical effect. All these canopies are coated with Indium Tin Oxide which at a certain angel to the incoming light would appear gold to the observer in a certain angel to the aircraft. There are many photos that F-16's canopy appears gold. There are also many photos that F-22's canopy appears that same as J-20 as the photo below shows. I suspect the reason of F-22 appears "unique" is USAF giving more PR attention to F-22 by employing artistical centric photographers.
These tinted glasses are commonly used in civilian application. Many fancy ski masks give gold, silver and rainbow effect.
These tinted glasses are commonly used in civilian application. Many fancy ski masks give gold, silver and rainbow effect.