Here's a great link if you'd like to learn more:
http://www.felderrushing.net/BottleTreeImagess.htm
I love the colors but wish they were a little more substantial in size. I tried grouping them all together to see how it would be with a whole tree of these smaller bottles. But decided it was "too much".
So I think I'm going to use them as "accent" bottles with the majority being clear larger bottles. Now I've got to start my "clear" bottle collection.