Both my KK's have orange trim around the b+w decals. The 99 in the catalogue does have red paint on the head tube, and it looks like his Hei Hei has red trim around the decals, not orange (but again, it could be the picture. I wasn't sure.) Definitely no Hei Hei listed in the catalogue I have found from 2000. A little Kona mystery to add to the pile ;-) Possible explanation might be that they had different decals in different countries, if say they were produced in different countries (the decals not the frames.) Early Kona's in parts of Europe were called "K mountain bikes", and sometimes the colours varied depending if it was American or Canadian, and presumabely Europe too. My KK's are from the states, so maybe yours are different because they are from the UK? And perhaps the Hei Hei was available (leftover frames perhaps?) in Europe in 2000 but not in North America. Perhaps his Hei Hei actually is a 2000 then, or a 99 or some other year whose country of origin is as yet unknown. Hmmm. The serial number could clear up the year mystery at any rate.
Kona never seem to make it easy, do they...