Well, it turns out that I’m a little short on original Japanese silver K4 pics.
Hopefully this photo taken back in the day will get the idea across:
(click on the images below for a larger view)
The JDM silver K2 and silver K4 are closely aligned at first glance as they both retain the blue tank stripes and silver paint. However, with the introduction of the K4, Honda adjusts the silver paint code and changes the tank & side cover emblems to the later K3-K6 design. The silver K2/K4 paint differences are the part numbers, color code and name change. Also, some may find it interesting that the K3 model was not released in Japan. Anyone know why?
K2: NQ = silver metallic custom
17500-341-670NQ Fuel tank
83600-341-701NQ Side cover, left
83700-341-701NQ Side cover, right
K4: UF = armor silver metallic
17500-341-810UF Fuel tank
83600-341-701UF Side cover, left
83700-341-701UF Side cover, right
Notice how the K3 is missing from the Japanese parts book cover: