I'm not sure which lens Blue Iridium uses, but the reason they have the yellowish tint is because the actual lens is likely the persimmon lens with the iridium treatment.
The Iridium part means they pretty much superheat metal till it fuses to the lens. This is the tinted part and they can control how much light it lets through really really well.
So you still see the original lens color (persimmon) and when the light hits it, you see the blue tint.
The lenses are at 30% so if they do use the standard persimmon lens (60ish%) then the persimmon is blocking and additional 30%.
Assuming the Fire Iridium also uses the persimmon lens at around 17%(too lazy to actually look). It's blocking around 45% which makes it a lot more reflective.
Reason that the Vr28 iridium isn't as reflective but blocks more light is cause it is using the vr28 lens which has a 28% light transmission with the iridium treatment at only about 15%... so they are still pretty see through but uber dark already.
Exciting stuff. Hope this kinda explains why they aren't totally reflective/shows orange through.
