I watched the same video I think. A bearded dude with glasses right?
Most mirrors have a silver backing and if you used clear blue glass you'd have mainly a silver tint with a possibly visible tinge of blue.
If you used a clear green glass, you'd have the green tinge.
And those videos and the articles are all that person's experience of the mirrors. Some people are color blind or don't see at the same exact spectrum like another person.
So, it's really a matter of personal opinion.
I see in most mirrors the silver, but like already mentioned, in smaller handheld mirrors, I've noticed the green too.
But for me, overall, most mirrors have a silver tint. :{