Looking at the empty Perrier and San Pellegrino bottles about to go into my recycling collection, its occurred to me that having regard to the “ten green bottles” drinking song / nursery rhyme that perhaps once more glass bottles might have been green.
Is there any history or mystique regarding green glass for bottles?
my guess would be that the green colour in old glassware came from impurities in the components and that absolutely clear glass bottles would have been harder to make and therefore more costly.
America here and I’ve never heard a green bottle nursery rhyme.
Bottles are often green to have a colored bottle that reduces light interaction with whatever is in it. Sometimes they want a colored bottle so people can’t see the product really well. Think of sediment of the product in the bottom. Since I don’t know the rhyme you speak of, I can’t say why they’d be green for any reason other than they had green available.
I know that you have to ad compound to get clear glass or it’s not clear.
Green and particularly brown also protect the contents of the bottle from sunlight to some extent. Not too important for bottled water, but fairly important for beer and wines that you’d like to have around for a while.
Since other colors should also give the same protection, the choice of green and brown may be simply traditional. Perhaps those pigments were cheap and easy to work with?
“Ten green bottles, standing on the wall.
Ten green bottles, standing on the wall.
And if one green bottle should accidentally fall
There’ll be nine green bottles, standing on the wall.
Nine green bottles, standing on the wall.
And if one green bottle should accidentally fall
There’ll be eight green bottles, standing on the wall.”
(continue on in this vein down to “no green bottles, standing on the wall.”)
Is this really not known in America?
Yes, green and brown glass are the result of very small quantities of impurities. Making colourless glass is much more challenging, so much so that getting even a small amount of recycled green or brown glass mixed in with the clear will reduce it’s value.
American song 99 Bottles of Beer
Wiki notes it derives from Ten Green Bottles.
Just like the Yanks. Everything has to be bigger. 
Everything is located farther apart so you need longer songs for the bus.
“Ten green grenades, hanging on the wall,
Ten green grenades, hanging on the wall,
And if one green grenade, should accidentally fall,
There’ll be no green grenades, and no fucking wall.”
I’m American, and I know the song; I know a few people who do, but it’s not common at all. Anyway, yes, it’s my understanding that a lot more bottles used to be green. (See also old books in which ‘bottle green’ is a color, usually for a coat. It’s a very dark green.)
Part of the reason for the word ‘green’ in there is just to make it scan.
Even “clear” glass is often a little bit green, as can be seen if you look through the edge of a pane of glass, so you’re seeing through 12" of glass instead of 1/8".
I was at a glassblowing demonstration last weekend & was told that colors in glass come from metals in the sand used for making it. The question posed was “why do you use silica sand instead of ordinary beach sand?” The response was that the iron that makes ordinary beach sand brown makes green glass. (I also found it interesting that the cranberry red glass was made with 24k gold mixed in the sand).
Which is why you can’t use window glass for making fibre-optic cables - it isn’t clear enough. A thickness of more than a few inches of window glass is effectively opaque. The green colour is due to traces of chromium, IIRC.