I believe he was referring to the bright nickle-silver reel seat hardware in the Orvis photo. I too feel it counter-productive. I darken nickle silver hardware with gun-blue - to include the ferrules. Just looks nicer that way. Trout in skinny water notice flash from shiny things rather quickly - their lives depend upon it.
Not surprising that someone from Montana would catch my drift! (terrible pun, I know). I like the idea of blueing, much better than electrical tape.
😉
Rant on: Maybe it's just in California-Oregon-Idaho, where I've fished a bit, but when I see folks with the nickel-plated grapho-carbo-nano super-shooter, white or pink wicking-material shirts, stomping around the stream to areas where they can cast easily, I head up to the next couple holes as fast as I can. Rant off.
Because trout is a predator and will chase anything that moves or glints. Most of the time they aren't taking fly at all. Its just that fly fishermen go out when the sun is shinning and the flies are hatching. The other 70% of the time a lure is a far better option. And especially a sunken lure in a deep pool where the bigger fish like to hangout below rough and therefore well aerated water. Plenty of oxygen for them.
Uh oh, rant on again: I think we may be doing things differently since I respectfully disagree with just about everything in this post. The trout I go after don't chase anything that moves or glints, they carefully inspect whatever goes by. Fly or lure, the trout I'm familiar with like it to be presented a certain way, whether purposefully done or not. I also don't go out fishing in full sun, and rarely do the flies hatch at this time.
Last, trout are not in the 'rough' water for aeration. Oxygen is supersaturated (especially in the daytime) in most rivers that support trout. Trout are typically making decisions based on energy gained to energy expended, cover from predators, and interactions with other fish (competition). Physical controls like temperature can also drive behavior, but I'll stop now while I'm only fairly annoying. Rant off.