Tying Canadian Fly Patterns: the Crevette-Mouiller (by Gérald McMullen) 

This fly has an interesting colour scheme that is meant to imitate a shrimp. The name means "Wet Shrimp" and I'm sure it will work as well on the West Coast for Pacific salmon, as it does on the East Coast for Atlantics.
This fly was taken from the book "A Compendium of Canadian Fly Patterns" by Robert H. Jones and Paul C. Marriner, Gale's End Press, Fly Fishing Canada Publications, 2006.