I have puzzled over the color of this water bottle since the day it arrived. I considered Teal but it is not blue enough and teal was not made until 1954 while I believe this water bottle to be circa 1940. I also considered Emerald which would be in the right date range but I think Emerald would be a little greener. I would certainly like to hear what your opinion is. Until then, we will call it aquamarine.