Green River swizzle sticks came in different varieties. There were solid glass rods and hollow glass tube varieties. The solid glass sticks came in cobalt blue, emerald green, and the occassional black. The hollow tube version had paper inserts with the name of the business, such as restaurants, hotels, taverns, and wholesale liquor stores. The color of the labels inside these hollow glass tubes were white, light green, and mustard yellow.
Dates ranged from about 1935-1940 with the predominant years being 1936-1939.
If you have additional information or examples of such Green River Whiskey swizzle sticks, please feel free to email me.