There is more than one version of the Riedel signature cane. John Simmonds wrote an article about signed Riedel weights in the April 2009 issue of the PCC Newsletter. Both have a capital 'R' inside a shape like a fat vase with a flowery top. They come in blue and brown versions (and maybe wine red), in a plain white circular cane.
If you Google 'Riedel signature cane' you should find a link to a pdf of Marek Kordiasiewicz's talk to the 2009 PCA Convention - that has an image of a Riedel signature cane in it.