It seems that most dry fly dressings, whether for collar or parachute style flies, call for hackle that matches the wing, not the legs, of an insect, and that doesn't make a lot of sense to me. Shouldn't hackle be either a match for a bug's legs or be as invisible as possible (as in a pale dun) so that its only purposes are aerodynamic, stability, and, perhaps, to create dimples on the waters surface?