Day 196-Mulberry (formerly identified as Lilac)
This is a Lilac water bottle made in 1959 or 1960. It is not etched Blenko on the bottom but I know that it is Lilac because I purchased it in 2004 and Violet (the only other color that is even close) was not made until 2005.
Blog Update July 31, 2013: I warned you at the very beginning that I was not an expert. I hope you heeded that warning. New information from a trusted collector has me convinced that this is an unmarked Mulberry bottle. That collector has a Blenko piece which was only made in 1958 and is purple in color and therefore has to be Mulberry. They tell me that Mulberry has more of a gray appearance than Lilac or conversely that Lilac has more red in it. I have posted an additional photo with this Mulberry on the left and an etched Lilac on the right so you can see for yourself. Undoubtedly, there will be additional corrections made as we learn more about Blenko colors. You can trust when mistakes are discovered they will be rectified.
This is actually a Mulberry water bottle, made in 1958, evidently before the etching process was established.