Actually, it's most often a yellow tint and there are several methods of accomplishing it. The coloration on actual canopy glass can be from actual tinting of the glass or in several cases a thin coating of Indium Tin Oxide - which gives it a slightly gold mirrored look. F-117s, F-16s and F-22s spring to mind for good examples of this.
There's the method of dipping the canopy into colored Future floor polish, but every photo I've seen of this method looks uneven. Some have suggested using actual window tinting film, but on compound curves this won't fit the curves.
For my F-117A that is in progress now, I will likely just get some Tamiya clear yellow and airbrush a light coating on the inside of the canopy before painting. An airbrush will be the key here I think as hand brushing or dipping won't provide the even results I'm looking for.
Did this help ya at all?
Brian~
"I may not fly with the eagles.....but weasels don't get sucked into jet engines!"