Yes but I asked what colour is it.

The second moving circles didn't work for me either for some reason. Is there anything you have to do, like, stare at something for so much time to make them work?

To Lord Vulchur: What ever color is reflected in it.

That was rethoric question

But what happens if nothing is reflecting in it?

In the same way water is blue, I'd say a mirror is green-ish.

Ever looked at the edge of a thick piece of glass?

No, why?

It's 'green-ish'...

Water is actually transparent. But it seems green or blue either because of what's in it, or because of what it's reflecting.

When I swim in water it's yellow.

That shouldn't be a surprise.

Water is actualy slightly blue, but you need an awful lot of it and an absence of sky to see that it is slightly blue. Even water molecules would be able to absorb some of the spectrum, so it should have a colour... it's just very faint.

Glass is green due to impurities in it. Interesting fact: if you took the glass that fiber optics are made of and made a block thick enough to have the same clarity as a half inch thick pane of glass, it would be half a mile thick.