T-fencing is the ranch standard - and T-fencing can last 40-50 years, particularly if wood is avoided. There are numerous examples of > 40 year welded wire fences in the Valley that are still fully functional - except for the wooden corner posts. Therefore, we are opting for steel T-posts with steel corner, gate, and support posts.
There are some trade-offs on painting the fence posts, as there are two mutually exclusive goals. The first goal is to minimize the visual impact of the fence. The second goal is to minimize deaths of wildlife running into the fence because they can't see it.
As far as wildlife, we need to consider deer, bear, coyotes,cougars, owls, various raptors, grouse, and songbirds. Of this list, the only animals that seem to be at risk if we choose a more camouflaged fence are the grouse.
That being said, local grouse are ruffled and dusky grouse, not sage grouse. (Sage grouse WOULD have trouble with a camouflaged fence (sage grouse are the not sharpest knives in the drawer) - but sage grouse are not found locally).
Some observation of local grouse near the Ranch - in particular, watching a male ruffled grouse fly straight up a Ponderosa Pine and perch about 50' off the ground - tend to suggest the local grouse can deal with an 8' fence.
Note also that it is easier to put some sort of visual marker on a completed fence (like sage grouse tags) should some issue arise, than it is to camouflage paint a completed fence.
(As a comment added three years later, there were some initial problems with both quail and grouse. However, after the first year, both species seemed to have learned how to negotiate it. Note that the presence of quail on the property dramatically jumped after the fence was installed, suggesting they are actually taking advance of the fence. (The number of grouse remained unchanged.)
For determining the fence color we painted a number of sample fence posts and placed them along the most visible part of the proposed fence run. We watched the posts during different lighting conditions and determined that the NFS brown color is the best match for a minimum visual impact fence. (This exercise was a bit of a surprise, as we expected the best color to be lighter. That being said, the NFS got their brown color somehow (probably not randomly selected) and it does seem to be a good choice.)