What often gets missed in these discussions is the fact that animals we pursue do not see what we see. If we're talking a Vassili Zaitsev stalking a Major Konig, a stainless rifle might not be the best tool. However, animals do not see the same bright colorful landscape that humans see. We can add $50 of Krylon to our new rifle and make it invisible to each of us. For the animals we are pursuing, in their mostly grey and black world of vision tinged with light shades of blues which can be compared somewhat to what a human with red green colorblindness sees, they don't see the intensities of colors which we see daily and which we try to hide by "camoing" our rifles and bodies.
However, even though they see a very dull world in front of them in comparison to the color-filled vision we have, they have an ability to detect movement of even the most obscure item in their range of vision. For example, a hunter in bright orange vividly stands out to us as its supposed to in the field. For a member of the canine species, they see the same orange as a very dull "tannish" color that blends into the other things in their normal range of limited colors and it is almost indistinguishable for them among other surroundings until it moves, even slightly.
If Ronald McDonald in his work clothes remained motionless while calling coyotes, he'd probably do as well as the rest to us would in a ghillie, again as long as he and his rifle remain motionless at critical times.
