Here are my pair of California One Piece Transpositions, CD 201, in the two listed colors, blue aqua and green aqua. All of the California transpositions are rare, with the 201's ranking third on the Cal rarity scale. These examples are very clean as most suffer damage under the upper umbrella and around the base. This was a poorly designed insulator by California as the glass is very thin around the lower wire groove where you would expect a lot of mechanical stress.

From what we know of early California glass production, there should be California Blue color examples, but as of yet, none have been reported. I think it is likely this color has just gone unnoticed by its owners. There are rumors of the existence of a purple California CD 201 in an east coast collection. In my mind a purple Cal 201 is unrealistic, but a veteran east coast collector confirmed its existence to me, but the owner was an early collector/doctor who has since passed on and his collection was lost to the hobby.