Byron, sorry that some folks seem to get sidetracked... I appreciated your question and it deserves an honest reply.

As far as your original question, yes, I do pay attention to materials regarding how they look in the water versus how they look in the water. I first noticed the problem when I began tying scud patterns for my favorite spring creek. I purchased what looked like just the right color dubbing that I would need and then discovered it would turn almost black when wet. This was for an olive pattern. I then began paying closer attention and even started blending some of my own colors. Most of the dry fly dubbing materials that promote themselves as waterproof, usually maintain their colors. But many of the more coarse dubbings for nymphs and such tend to go a bit darker. The few exceptions I have found have been those from Dave Whitlock and Arizona Dubbing.

I tie a scud with Krystal Flash as a ribbing and I like to demonstrate how the rib adds life to the scud when wet, so I usually put it in my mouth and show off the colors that way when demo tying. (I'm sure someone will go off on the dangers of putting such things in my mouth... - too bad, I still do it )

On the other hand, I have found that a generic dark-colored mayfly nymph usually works better than any specific color. I let the fish choose.

Kelly.