Most dark hendricksons will have that grayish dark body, while I've found that the red quill usually has a distinct rusty, reddish, even a little orangish color to it. Just check out the bugs and see what color is closer. The fly names can be confusing, especially if you order online (which I'd only recommend as a last option unless you've heard good things). I've ordered march browns before and got what i would call a gray fox, as well as some other interesting spin-offs. It's better to see them in person. Good luck.