It is funny you posed that question, as I just brought home a new to me 28" 835 Waterfowl in Mossy Oak Shadow Grass. I have a 24" 835 Turkey gun in Advantage Timber I bought in 2001, and I owned an 835 Deer & Waterfowl combo years ago that was in the original Realtree All Purpose Green camo (circa early 1990's).
I handled an as new, unfired 835 Deer & Turkey combo yesterday that was in the original Realtree Extra Grey. That was also a pattern from the early 1990's.
I would say that you could not count on both hands and feet the number of patterns that has been applied to this great shotgun since it was introduced in 1988.