While I certainly am not a fly fishing historian I have noted something that has me confused. There seems to be a great variation in what the color "Dun" means in a hackle. A dictionary definition says it is a "dirty grayish tan". My old Universal Fly tying Guide by Dick Stewart has a color chart that confirms this. Yet most prominent breeders, (and dyers), of hackles have unreasonably diverse ideas of what the various shades of Dun are. To my surprise, the biggest supplier has not even the slightest hint of any tan or brown in any of his Dun hackles. Another popular producer sells Medium Dun hackles that all dark tan. With almost all of the so called Dun hackles being dyed, it would seem logical that the breeders would have better control.