Ok, I got confused when replying.You're thinking of the FLIR? I meant the small windows distributed around the fuselage. Take a look at the EODAS side windows on the nose in these photos: View attachment 52745
View attachment 52746
However, problem with degerming colour (therefor material) of EODAS window is that the lens is in front of a housing whose interior colour is unknown and likely to make the lens looks much darker than it really is.
I have found a similar photo of F-35 here. Compared with your second photo of J-20, you can see the same effect where the canopy has no golden hue but merely dark grey/green, while the EODAS window is purple reddish.
