Martin, I am pretty sure I saw one in Europe on Bert's forum. They really are pretty good looking in the flesh. The yellow is a bit subdued, but not a washed out pastel and looks good with the black of the drive train components.
As far as yellow bikes, Suzuki motocrossers and Yamaha road racers come to mind. I think part of the reason you don't see a lot of yellow around is that back in the 90's the EPA outlawed some of the pigments used for yellow paints because they contained chromium which was determined to be highly toxic and bad for some endangered fish or something somewhere.