Day 178-Periwinkle Blue
Periwinkle Blue is a light blue color that is not cased. It was a specialty or experimental color made in 2007 (and again in 2011) and has not yet been made a catalog color. It has a “dusty” appearance when you see the actual glass which does not show well in photographs. If you find a non-cased pale blue and it is etched 2007 then you have Periwinkle.
The photograph above compares an Azure Water Bottle with Periwinkle Blue (on the right.)