Most people never see any in colors other than what you find food and drink in at your local supermarket; typically clear, brown and green. And Coke bottle "seafoam."

It's quite fascinating, once you get down inside it, though... there are actually serious collectors all around the world, and really unusual/rare pieces might sell for $$$ hundreds on eBay.

For me, it was just a great meditation and hobby... that just happened to turn into cash.