Re: Got Rats?
Just received my copy of Keith Fulsher's "Atlantic Salmon Fly Tyer: A Memoir", and -- whaddya know? -- his recipe for the Rusty Rat calls for fluorescent orange floss, not rusty orange. So I guess there's my answer.
(But I think with that dramatic a substitution it really ought to be called something else, perhaps "orange rat", to avoid confusion with the original.)