table cloth and it's light blue coloration? My senses tell me this has a water theme?
I'm not sure. The simplest explanation for the table cloth color is that it matches what they use at Kokufu, which is I believe a strong motivation for Boon. The next simplest explanation is that it looks nice, calming, and doesn't visually interrupt the show. It's felt and is used throughout our exhibit. If you've seen photos of other shows in Japan you know that the color is not always blue; I've seen white and red at least.
Coloration of oak pot and kusamono pot, basically a creme or white variation. Do they need to be strongly different color wise?
Well, I think it's easy to over-complicate something like display. My opinion is that the "rules" are not really rules but more like enumeration of something that is difficult to put into words.
At BIB we study display every month at our meetings. The meetings are a lecture style with techniques for growing trees and styling. At the end of each meeting we set up a display or two and test different elements with the main tree to see how they feel and look. Often the height of the stand, the size of the accent, the texture of the accent etc are changed. Also up in the air are the arrangement of elements based on the visual flow of the trees and accent. What is set at that point is the pot that the tree is in.
So - I think the important thing to think about is how the display makes you feel. Is it thoughtful with diverse elements that work together and that "feel right?" In this case the oak's pot is quite old, and texturally compliments the tree while the accent plant pot is newer and in my opinion matches the youth of the plant well. The fact that they are similar color isn't an issue for me. But if it were an issue for someone else then a different accent could certainly be used. I'll admit that I was more concerned about the type of plant used and it's origin than the pot that it is in.
Another potential criticism via PM that came to me: the stand that the oak is on, a carved root round, and the stand that the accent are on are very similar. Perhaps it would be better to put the Oak on a taller root stand, or a stand that was more table-like.
If you've never seen a Kokufu album you might try to take a look, they contain many great examples of displays. You can gloss over the details if you're not careful, but there is a lot of good info in there.
Cheers,
Eric