This is a Willy Self fly. It's not my pattern. They work (surprisingly well) all year long. But they really work well in Winter. It's all part of a cutting edge new theory called "Not Matching the Hatch." This isn't exactly how Willy ties them. But it's close enough. The orange stuff is Edge Bright, which comes as flat plastic rectangles you cut into thin strips. And then wind onto the hook. There are a half a dozen colors but hot hot hot orange seems to be the most important one.
Damn fish got his licks in on me in return. I took the hook out of his mouth and held him up for a photo. And he bit me as I held him. Tooth went right through the web between thumb and forefinger. In one side and out the other.