Taste is a funny thing. I love all of them besides the blue (I'm sure this one has it's place for the right tree)....The final one pictured is remarkable.
I echo Jason's opinions. My first thought on seeing the blue glaze was the it was beautiful but I couldn't visualize what kind of tree could keep that pot in its place.
But pots can be enjoyed just by themselves. They don't need to have a tree in them to be complete. One shouldn't try to imagine a tree to pair with a nice pot. You guys are being too practical. But I actually have great little twisted, windswept style Japanese quince (toyo nishiki) with little white and pink flowers that would match very well with that blue pot.
I wasn't familar with Gelsemium sempervirens, so I googled it. Very nice match for the blue pot. Do you have one with a nice trunk? I'd be interested in seeing the plant and the pot together.
Wikipedia reports that the sap of this plant is toxic to some people so you may want to get disposible gloves to do any pruning on this. Also, all parts of the plant are toxic when ingested (children may mistake it for honeysuckle), and it tends to kill honeybees.
And hey, all b-nutters: Paul makes great pots! As the proud owner of two of his pots, I can attest to to his high standards in both contruction and aesthetics. His prices are fair as well.
Paul, if you plan on using the blue pot with the Gelsemium sempervirens will you please post the results and share with us how you went about training it to become a bonsai?