Read an summation a few yrs ago from a university in the states, unfortunately I don't remember where I saw it, but it was a study, concerning the rods etc. in various ungulate's eyes.(technical stuff was way more involved than I cared to be bothered with)
It was mainly concerned with ungulates colour perception. Two things I remember were: deer see blaze orange as brown, as they do trees, and, deer see blue(bluejeans) as we see neon pink.
Don't remember where I saw it, I suspect it came from LSU.
I've wondered about that with the silver barrels as well. If you're considering one and worried about it, I'd bet Louisana State University was the one that did the research.